Hevi Sand presentation SAIF 29/9/2010
AMCOL Overview
June 2010
AMCOL Overview
June 2010
AMCOL Overview
June 2010
n US-listed (NYSE:ACO); Incorporated in 1927.
n Global leader in bentonite performance application products and services l Industrial and consumer end markets
n Innovation and market driven development pipeline; Over 100 patents in force.
n Global bentonite mining operations.
n Responsible corporate citizen (we understand our role in the community)
AMCOL Product Markets
AMCOL Global Entities
September 2010
28 Operating Companies
Amcol Global Locations
Excellence through research and Development The H.S. Process (patented)
Hevi-Sand® Diary
• WHY • 2005 commodity boom, supply concern
for Amcol and its customers • 2005 desire to sell Hevi-sand Globally in
all Amcol locations • 2005 started investigating possibilities
and market size. • 2005 started investigating process
requirements.
Hevi-Sand® Diary
• 2005 started speaking to current suppliers re supply agreements, developments, projects etc
• 2005 Failed to get a meaningful response from suppliers, started looking for a suitable deposit.
• 2005 Continued process research. • 2005 investigated costs and likely
investment. • 2005 investigated customer product wish
list
Hevi-Sand® Diary
• 2006 started looking seriously for a suitable reserve. (found Batlhako)
• 2006 started doing pilot work on the new process.
• 2006 started board approval process for a probable US$50m investment.
• 2007 agreed purchase of Batlhako.
Hevi-Sand® Diary
• 2007 continued pilot work on the new process.
• 2008 Bought old Paul Kruger spiral plant Thaba to ensure continuity of supply to existing customers.
• 2008 Continued tuning the process.
Hevi-Sand® Diary
• 2008/9 Eventually all pieces in place and ready to go.
• GLOBAL FINANCIAL MELTDOWN • 2009 Board approval to build the plant. • 2010 July commissioning new plant
Amcol South Africa
ü Feb-09: Acquired controlling interest in Batlhako Mining Ltd, Ruighoek Farm.
ü Initial indicated resource: 11 million tonnes.
ü June-10: Began commissioning 100KT/A chromite processing facility
ü Sept-10: Acquired remaining interest in BML.
South Africa Chromite Mine Investment
Geology of the South African chromite Deposits
BUSHVELD COMPLEX RSA
Amcol Mine Location
Chromite Formation
• Crystallization is the (natural or artificial) process of formation of solid crystals precipitating from a solution, melt or more rarely deposited directly from a gas. Crystallization is also a chemical solid–liquid separation technique, in which mass transfer of a solute from the liquid solution to a pure solid crystalline phase occurs.
Chromite Formation
• Crystallization separates a product from a liquid feed stream, often in extremely pure form, by cooling the feed stream or adding precipitants which lower the solubility of the desired product so that it forms crystals.
• Well formed crystals are expected to be pure because each molecule or ion must fit perfectly into the lattice as it leaves the solution. Impurities would normally not fit as well in the lattice, and thus remain in solution preferentially
Chromite Formation
Chromite Formation
Chromite Formation
Chromite Formation
Crystal stuck together in a silicate soup
Chromite Formation
Crystals stuck together in a silicate soup
Chromite Formation
Chromite Formation
Traditional Chrome Ore – Supply Chain
MINE
MET GRADE 75%
CHEM GRADE 15%
FOUNDRY GRADE10%
FERRO CHROME PRODUCTION
CHROME PLATING
PROCESSED BY DISTRIBUTOR
TRADERS FOUNDRIES
Recent and Historic Market Conditions
• UNDER SUPPLY , SHORTAGES AND RUN
OUTS • PRICE VOLATILITY • VARIABLE QUALITY DUE TO SHORTAGES and
BY-PRODUCT STATUS
• LITTLE OR NO TECHNICAL SUPPORT
• MARKET SUPPLIED BY TRADERS
Traditional chrome sand production
Traditional chrome sand production
Traditional chrome sand production
Magnification of Chromite in lump form
X20 X10
Traditional chrome sand production MINE FINES
Traditional Processing Ball Mill
Typical Spirals Plant
Spirals Plant
Traditional Processing: Traditional Spiral Processing
Humphrey’s Spirals – Washing and Separation
Traditional Chrome Processing Layout
Traditional chrome sand production
• Typically less than 3% of ROM (run of mine) chrome ore ends up as Foundry Sand.
• Traditional production methods would be financially unjustifiable without ferro-chrome production
• Foundry sand is a by-product for FeCr producers.
H.S. PROCESS Plant Requirements our Conclusions
• High Yield to be cost effective • We needed to understand the
impurities and there effect on casting quality
• We needed to remove the impurities while maintaining chrome crystal integrity
• We needed low power and water usage due to availability shortages in RSA.
H.S. PROCESS Customer Requirements our Conclusions
• High Quality Consistent Product. • Continuity of Supply • Price Stability • Local Stocking Points • Technical Support and Advice • Different Size Fractions, and Distribution
curves (permeability, and penetration control)
• Reductions in Resin and Catalyst additions (gas generation)
• Better High Temperature performance (fusion)
H.S. PROCESS Market and Product Contradictions
• Order Specifications, different everywhere and in many cases out of date or not achievable.
• Test procedures, different everywhere and very often unspecified.
• Sampling Procedures often unspecified • Chemical analysis methods and
procedures unspecified and incorrect. • Due to the disparate nature of the market
no unification of testing and procedures has developed
H.S. PROCESS Conclusions (yield required)
MINE (100%)
MET GRADE 5%
CHEM GRADE 5%
FOUNDRY GRADE
75%
FOUNDRY
WASTE 10%
REFRACTORY GRADE 5%
Financial justification requirements
Magnification of Chromite lump (Yield)
X20 X10
Research Utilize the whole ore body
Typical edge of seam fines
Research Utilize the whole ore body
Washed and crushed Lump Fines
Research Utilize the whole ore body
Silicates attached to chromite Grains
Research Utilize the whole ore body
Whole Seam washed and crushed
Research Utilize the whole ore body
Close up of Whole seam washed and crushed
Research Utilize the whole ore body
Crushed Lumpy Unwashed
Research Utilize the whole ore body
• Wash crushed lumps classified but without separation
Research Utilize the whole ore body
Research Utilize the whole ore body
Particle mineral map from the -1180 +850 μm fraction of the AMCOL Chromite sample via QEMSCAN analysis.
Minerals Chromite Enstatite Anorthorite Hematite Phlogopite Others
The Silica is actually low melting point silicates.
Research Utilize the whole ore body
• Silicate type prevalence changes with grain size
Conclusion Utilize the whole ore body
• There is NO SILICA, all these impurities are essentially forms or phases of Magnesium silicates and their prevalence is associated with size fractions
• They have melting points which range from 800 – 1800℃
• Therefore lowering the levels of most of these impurities increases the fusion point of the final product.
Fusion Testing 0.4% silicates at 1600c
Fusion Testing 0.8% silicates at 1600c
Fusion Testing 1% silicates at 1600c
Fusion Testing 1.5% silicates at 1600c
The HS PROCESS was born
• It became clear to maximize yield without damaging final quality required a process which removed the surface contaminates on the chrome grains without damaging the crystal integrity
• Therefore the impurities should be shocked from the chrome grains and any remnants abraded away as the impurities are not soluble.
Conclusions from Old Spiral Technology
• We also knew from our old spiral plant, that by removing the impurities using spirals and water caused massive losses and nearly all the useful fines ie up to 70% of the feed was lost.
• We also new the high power and water demand, of ball mills and spirals, not to mention the crystal damage inflicted by the mill.
• These factors made a modified spiral plant impractical.
View Of Mine-workings with new plant in distance
View Of Mine-workings with new plant in distance
H.S. Processing Plant
Plant ROM Feed
Impact Mill
Sizing Screen
Wet Plant Attritioning Units
Attritioners
Up Flow Classifier
De-Watering Bunkers
De-Watering Bunkers
Tailings Dam
ROM Feed Circuit
Wet Plant Feed Circuit
Fluidised Bed Dryer & Refining Building
H.S. Process Silicates Separation Technology
MAGNETIC & ELECTROSTATIC SEPARATION OF IMPURITIES
Electrostats
MAGNETIC & ELECTROSTATIC SEPARATION OF IMPURITIES
Rare Earth Magnets
Ultra Separation Plant Science
• Electrostats • Rare Earth Magnet
+ + MAGNET
Sand Flow single Layer
Chromite
lost charge Silicates
Hold Charge
Sand Flow single layer
Slicates
Non Magnetic Chromite Magnetic
+ + + + Magnet
Rotation Rotation
Multi-Deck Screen
Multi-Deck Screen
Storage and Re-Blending of Size Fractions
Packaging Plant
Packaging Plant
H.S. Process Plant Overview
• WET Process-: • LIBERATION – Rotary Impact Mill • PREWASH – Screening & Clay Removal • ACID WASHING – pH control & cleaning • DRY Process -: • DRYING – FUIDIZED BED • MAGNETIC AND ELECTROSTATIC SEPARATION • SCEENING AND DE-DUSTING • SIZING AND CLASSIFICATION • IN LINE TESTING • PATENTED PROCESS
Waste Product results
• Silicates 95.3-97.8%
Ultra Hevi-Sand Product results
• Silicates 0.3-0.8% • Chrome 47.5 – 49% • Iron oxide 24 – 26% • Chemical analysis
maintained afs 25 to 70.
• Acid demand Ph 3 less than 5ml
Great Result but we had some Problems
• PROBLEMS-: • Product Segregation and large tramp silicate
particles • Variable set times and strengths on some binder
systems • Inconsistent turbidity • Low packing density
Segregation
• PROBLEMS-: • Even with in line sampling we had complaints-so
we investigated sampling • We had installed a low energy static blender
which we thought may have caused some issues • We had designed steep angle low segregation
hoppers but questioned there effectiveness
Investigation into AFS Discrepancies Hevi-Sand Production Facility
Ruighoek, Republic of South Africa
AFS Discrepancies
• AFS grain fineness values are consistently reported coarser
(lower AFS) at customer sites than measured in the
Plants QC laboratory
• Why?
AFS Discrepancies
• Key issues at play The first is Segregation
refer to the video from US silica for a good overview of
segregation in bulk aggregates
Segregation
AFS Discrepancies
The finer material has a tendency to flows through first which results in some
stratification in the bag –particles segregate based on size, shape and density
The plant has installed in anti-segregation cones in key places as well as having 72 degree
angles on holding bins to prevent segregation However, segregation is very difficult to
eliminate completely
AFS Discrepancies
• Key issues at play The second is Sampling
“Grab” or hand sampling from the top of the bag does not yield a
representative sample ( Segregation during filling suggests a coarser sample will likely be obtained)
Sampling spears are often used to sample bulk bags of grain or sand-given that they can penetrate at least ¾ deep in the bag and an
appropriate spear and technique is used Some spears take samples from multiple heights via a rotating inner shaft
or sliding gate, after which the subsamples from the different heights are combined prior to testing
Examples of Various Sampling Spears
• Due to the hardness and particle size of Hevi-Sand it makes using these spears difficult
• If a spear has a single unblocked opening and is inserted in the top of the bag it will sample material from the top preferentially regardless of the depth inserted
• Some spears are better than others but none satisfy the requirement of obtaining a representative sample!
Sampling
Sampling is defined as the process of removing an appropriate quantity for testing from a larger bulk, in such
a way that the proportion and distribution of the factors being tested are the same in both the whole (lot) and the
part removed (sample).
This has proven very difficult to do with a sampling spear
Sampling –Best Practice
Ideally multiple samples at random intervals should be take from transfer
point with a “pelican” style sampler that transverses the entire cross section of the stream and will not overflow during sampling, samples
should be taken from an established stream (at least 12” from discharge)- samples should then be combined and reduced to an
appropriate amount for testing. These principles are widely acknowledged in metallurgical, agricultural
and grain industry – Granted we are not dealing with grain but the same concerns and issues
regarding segregation and representative sampling are very much the same
• Inspecting Grain--Practical Procedures for Grain Handlers, MP-34. Federal Grain Inspection Service, United States Department of Agriculture, P.O. Box 96454, Washington, DC 20090-6454. 1991
• Grain Sampling, Book I. Federal Grain Inspection Service, United States Department of Agriculture, Washington, DC 20250. 1989
AFS Discrepancies
At the Hevi-Sand plant during transfer of our blends to our 25 ton holding tanks
for bagging a automatic sampler is used to sample the entire stream at regular intervals during filling -every minute-averaging more than 1 sample per ton
these subsamples are combined and sent to the lab for testing
Whole Batch Study
• Lots are given to our Hevi-Sand – Lots are no larger than 25 tons due to the
capacity of the holding bins the material is blended into
• An entire batch of typical AFS Red grade production was investigated at the plant to look at these issues
Whole Batch Study
23 bags were produced, the measurement from the auto sampler was 47.28 and this is the value that would appear on Certificate of Analysis (COA)
• 22 of the bags were tested as below - 1 bag used for “whole bag splitting”
- individual AFS on each bag taken via sample spear taken from the top of the bag ( Manual)
- A composite sample of the individual spear samples taken from the top of the bag (Composite Manual)
- 6 individual directional “side spear” samples on each bag to look for evidence of stratification in the bag
(side spear) - 6 interval samples from the flow resulting from the
discharging of the contents of the bag (flow sample)
Whole Bag Splitting
One bag produced was tested via “Whole Bag Splitting” The entire 1 ton bag was split and reduced down to the sample size needed for AFS
Value on COA = 47.28
Value from Whole Bag splitting =49.79
Average value from samples obtained from sampling spear in top of bag
AFS 43.91 Value for Composited Manual Samples= 45.65
Whole Batch Study
Whole Batch Study- Summary of Results
Sampling Method Average Grain Fineness Value
Composited Top Spear Samples 45.68
Manual Top Spear Samples 43.91
Whole Bag Splitting/Reduction 49.79
Average of All Side Spear Samples 49.09
Average of all Discharge Flow cuts 47.46
Side Spear Sampling
Sample Average Values across Bags in Batch
Side Spear 1 47.90 Side Spear 2 49.05 Side Spear 3 49.77 Side Spear 4 49.31 Side Spear 5 49.48 Side Spear 6 47.17
Manual top Spear 43.91 COA Value 47.28
Average of Side Spear Samples
Discharge Flow Sampling
Sample Average Across All bags
Flow Cut 1 48.25 Flow Cut 2 47.84 Flow Cut 3 47.72 Flow Cut 4 47.34 Flow Cut 5 46.83 Flow Cut 6 46.76
Manual top Spear 43.94 COA Value 47.28
Average of Discharge Flow Samples
Conclusions
• The top spear “manual” sample shows the largest amount of variation and is systematically lower than samples taken from the same material when flowing as seen in the COA value and discharge stream samples
• Whole Bag splitting also gives an AFS value that is close to the value reported on the COA
• Only individual spear samplings yield consistently low AFS values
• We are confident that the sizing on the COA reflects the contents of the bag
Conclusions
• Segregation is difficult to combat -anti segregation equipment reduces segregation
by re-blending the material during transfer -Each time material is transferred there is a
chance for segregation to occur • Sampling from the top of the bag even with a spear
yields coarse AFS results
• A potentially better way would be to sample the moving material during bag breaking, – sampling flowing material is a more preferable sampling
method
We Installed a New Conventional Blender
Conclusions Large Tramp Silicate Particles
• While we met our internal Silicate level Specification > 0.8%. Visually we saw large silicate particles.
• These particles were very difficult to remove due to their size and sometimes their semi-magnetic properties.
• This made it difficult for the electro-magnet separation equipment to differentiate them from small chrome particles
Conclusions Large Tramp Silicate Particles
Competitor Material
Competition material from UK
Similar array of small silicates Looks similar to February production under microscope
25 x magnification
Conclusions Removal of Tramp Silicate Particles by AST’s
Conclusions Removal of Tramp Silicate Particles by AST’s
Variable binder performance and ADV
• Problems -: • While we were achieving our target ADV values ie
>5ml at Ph3, we had inconsistent set times or low strengths with Furan resin.
• Increased acid wash did not resolve the problem • Neither did the undesirable increase in catalyst.
Variable binder performance and ADV
• Problems -: • We did not understand the data
• We did not understand the binders susceptibilities sufficiently
• We needed to investigate what we needed to
investigate
117
Investigation of Resin systems and Hevi-Sand
Resin systems
Main resin systems used with Chromite: • Thermal setting
– Shell process • Cold setting
– Sodium silicate/ Ester – Phenolic acid cured or Phenolic no-bake – Phenolic alkaline/ ester (Alphaset) – furan binders or furan no-bake – PU = Phenolic Urethane no-bake (liquid amine)
• Gas setting – Phenolic alkaline/ ester (gas phase) (Betaset type) – PU = Phenolic Urethane /gas amine cured (cold box type) – Silicate/ CO2
118
Resin systems and Hevi-Sand – cold setting
Resin systems
Main resin systems used with Chromite: • Shell sand: Usage: core or shell moulding 1 thermoplastic formo-phenolic resin 2 hexamine Setting type: quick setting by heating at about 160°C
Reach the melting point of the resin Hexamine generates additional formol to start the setting Resin becomes a thermo setting resin Hexamine generates ammoniac which accelerates setting
Old and efficient type system – 1,5 to 6 % addition rate Not really easily affected with sand quality variation because it contains a
large amount of resin and it is a strong reaction.
119
Resin systems and Hevi-Sand – cold setting
Resin systems
Main resin systems used with Chromite: • Sodium silicate/ Ester Usage: moulding and cores – large and medium 1- Sodium silicate 2- Esters (various types) Setting type: progressive and slow setting
by pH reduction + desiccation generating acid salt + Alcohol: Acid salt progressive pH reduction (neutralisation) Alcohol Gel of silicate
Quite old type system – 2,5 % to 3,5 % addition rate Difficult to regenerate - Quite slow to obtain full setting Sand Stays on the basic side after curing. Not really easily affected with sand quality variation because it contains a
large amount of Binder and it is a slow reaction with long bench life
120
Resin systems and Hevi-Sand – cold setting
Resin systems
Main resin systems used with Chromite: • Phenolic acid cured or Phenolic no-bake Usage: moulding – large and medium 1-phenolic resin named PF (Phenol-Formol) 2- Acid (catalyser) Acid types: According resin type and reactivity Setting type: poly-condensation + exothermic reaction 0,8 % to 1,5 % addition rate - Low reactivity – needs strong acid High influence: pH and ADV of sand, T°C, Acid dilution. Can be affected with sand quality variation because it contains a relatively
small amount of resin and it needs a strong acid
Mineral (low recycling)
Organic (more typical with chromite)
Higher reactivity
Phosphoric PTSA Benzene toluene
Lower reactivity
Sulphuric Benzene xylene sulfonic Benzene xylene Toluene sulfonic
121
Resin systems and Hevi-Sand – cold setting
Resin systems
Main resin systems used with Chromite: • Phenolic alkaline/ ester (Alphaset type) Usage: moulding and cores – large, medium and small 1- alkaline phenolic resin (very high pH) 2- various organic esters Resin type: Soda base or Potassium based Setting type: creation of alkaline salts + Alcohol to neutralise the area. The resin can then create progressively a gel (polymerisation) and can
reticulate slowly. 1,2 % to 1,8 % addition rate. Difficult to regenerate completely as it contains mineral residues. Very slow to obtain full setting through – easy to strip Sand Stays on the basic side after curing Some influence: pH and ADV of sand, T°C. Can be only slightly affected
with sand quality variation as it is slow and binder content is quite high.
122
Resin systems and Hevi-Sand – cold setting
Resin systems
Main resin systems used with Chromite: • Furan binders or furan no-bake Usage: moulding and cores – large and medium 1- Furanic resin 2- Acid (catalyser) Various Furanic resins type: UF FA; PF FA, UF P, UF PF FA to be chosen
depending on N2, price, free formol, reactivity… expected. Acid types: According resin type and reactivity Setting type: poly-condensation + exothermic reaction + Water 0,8 % to 1,5 % addition rate - Low to medium reactivity – needs strong acid High influence: pH and ADV of sand, T°C, Water content: Can be affected with
sand quality variation because it contains a relatively small amount of resin and it needs a strong acid addition to set at the expected speed.
Mineral (low recycling)
Organic (more with chromite)
Higher reactivity
Phosphoric PTSA Benzene toluene
Lower reactivity
Sulphuric Benzene xylene sulfonic Benzene xylene Toluene sulfonic
123
Resin systems and Hevi-Sand – cold setting
Resin systems
Main resin systems used with Chromite: • PU = Phenolic Urethane no-bake Usage: moulding and cores – any size. 1-Phenolic resin 2- Poly-isocyanate MDI 3- Liquid amine (pyridine type) Setting type: poly-addition of part 1 + Part 2 - exothermic reaction Part 3 is only a catalyser. Total binder 0,7 % to 1,4 % addition. The reaction generates a “reticulated polyurethane” resin (thermo setting
resin). Uniform and rapid setting after reaction started. Stripping can be difficult. Strong maximum strength is obtained rapidly Very quick setting time compared to bench life (for high productivity). Curing efficiency can be strongly reduced in case of water content in the
sand. High influence: pH, ADV or/and alkaline demand of sand Can be affected
with sand quality variation because it contains a very small amount of resin and the reaction speed and final strength can be reduced if the sand contains any residual acids.
124
Resin systems and Hevi-Sand – gas setting
Resin systems
Main resin systems used with Chromite: • Phenolic alkaline/ ester (gas phase) (Betaset type) Similar as Alphaset but using a gas Ester (methyl formiate) Binder usage: 1,2 % to 1,8 % addition rate. Some influence: pH and ADV of sand, T°C. Can not be significantly
affected with sand quality variation as binder content is quite high and as the gas addition is used in excess most of the time.
125
Resin systems and Hevi-Sand – gas setting
Resin systems
Main resin systems used with Chromite: • PU = Phenolic Urethane /gas amine cured (cold box type) 1-Phenolic resin 2- Poly-isocianate MDI 3- gas amine (Pyridine) Similar as PU-No-bake but using a gas Amine (methyl formiate) Binder usage: 0,8 % to 1,6 % addition rate. Very sensitive to water excess! Could be affected with sand quality variation because it contains a small
amount of resin; however a excess of gas curing can solve a reduced curing efficiency due for example to any residual acids.
126
Resin systems and Hevi-Sand
Resin systems
• Classification Organic or Mineral? - Acid or Basic?
Setting area Binder type
Acid Basic
Organic Phenolic acid cured Cold setting Furan
PU no-bake PU amine cured Alkyd resin (old types)
Mineral Sodium Silicate/ester Silicate/CO2
Phenolic alkaline/ Ester
127
Investigation of Resin systems and Hevi-Sand
Resin systems
• Foundry Comparison Summary - experience in France Competition
Amcol Lot66305 MinelcoProduction date DECEMBER 2010 MAY 2011pH 8,22 ?ADV pH 3 6,2 ?ADV pH 4 5 ?ADV pH 5 4,4 ?Initial curing rate slow not triedcuring rate very slow expected valuestrength development Slow/ under expectationexpected value24 H Strength < expectation expected value
curing rate not tried not triedstrength development not tried not tried24 H Strength not tried not tried
DetailsTrial from FMGC Furan Resimax 1014Bench lifeCuring time with normal cata > 30 min - no setting 10 to 15 minCuring time with quicker cata 15 min24 H Strength (standard) lower than comp
FURAN
PU
128
Investigation of Resin systems and Hevi-Sand
Resin systems
• Foundry Comparison Summary - experience in France Competition
Amcol Lot35101 Aumas Amcol Lot35216Production date MAY 2011 MAY 2011 AUGUST 2011pH 7,55 7,91 7,39ADV pH 3 4,5 3,1 3,8ADV pH 4 3,6 ? 3ADV pH 5 3 1,1 2,5Initial curing rate slow expected value expected valuecuring rate slow expected value quick and then slowstrength development Slow/ under expectationexpected value Slow/ under expecta24 H Strength < expectation expected value < expectation
curing rate expected value expected value Slowstrength development expected value expected value Quick24 H Strength OK but High value OK but < than Amcol< expectation
DetailsTrial from Manoir Furan HA 21R12 Furan HA 21R12 Furan HA 21R12Bench life 6 min 5 min 5 minRemark starts quick & then slow Curing time 60 min 25 min 60 min24 H Strength (dog bone) 6,25 6,5 6,2
Trial from Manoir PU? from ASK PU? from ASK PU? from ASKBench life not tested not tested not testedCuring time 21 Min About 25 min 41 Min
FURAN
PU
129
Investigation of Resin systems and Hevi-Sand
Resin systems
• Foundry Comparison Laboratory trials Industrial trial November 2011
Summary - experience in France big bag 51859 Competition CompetitionAmcol Lot35101 Amcol Lot35216 Plump - Thyssen Amcol 35136 Plump - Thyssen
Production date MAY 2011 AUGUST 2011 AUGUST 2011 JUNE 2011 SEPTEMBER 2012pH 7,55 7,23 ? 7,51 ?ADV pH 3 4,5 3,08 ? 4,6 ?ADV pH 4 3,6 3 ? 3,7 ?ADV pH 5 3 1,97 ? 3,1 ?Initial curing rate Not tried Not tried Not tried Not tried Not triedcuring rate Not tried Not tried Not tried Not tried Not triedstrength development Not tried Not tried Not tried Not tried Not tried24 H Strength Not tried Not tried Not tried Not tried Not tried
curing rate expected value very slow expected value Slow expected valuestrength development expected value Quick expected value Slow expected value24 H Strength OK but High value< expectation expected value < expectation expected value
DetailsTrial HA for Magotteaux Lab trial with PU 34201/172 From HAF 24 T trial with PU 34201/172 From HAFBench life 23 min 41 min 17 min 22 min 12 minCuring time 33 min 50 min 25 min > 50 min! 21 min1 H Strength (standard) 8 1824 H Strength (standard) 36 24 about 28 35 44
FURAN
PU
130
Investigation of Resin systems and Hevi-Sand
Resin systems
• What happens if the sand is too basic? Bench life Final strength
Shell sand NA NA
Sodium silicate / ester
Phenolic acid cured Furan binders
PU no-bake PU gas amine cured
Phenolic alkaline/ester (liquid or gas Ester)
131
Investigation of Resin systems and Hevi-Sand
Resin systems
• What happens if the sand is too acid? Bench life Final strength
Shell sand NA NA
Sodium silicate / ester
Phenolic acid cured Furan binders
PU no-bake PU gas amine cured
Phenolic alkaline/ester (liquid or gas Ester)
132
Conclusions Resin systems and Hevi-Sand
Resin systems
• Discussion about pH, Acid demand and Alkaline demand?
– The most important for our customers is to receive a consistent and acceptable quality that optimizes the defined binder process.
– Trying to tune the process with more acid washing risks damaging actual results obtained with PU or Furan, ie improving Furan performance may impair PU performance. Better grain cleanliness seems to be the best way forward.
– Competition sand does not always have a low pH but ADV at pH5 is can be lower: that means that we may have a buffer (like sponges) on/ in our sand which is activated “post ADV” during curing. If we over acidify the sand, it treats the problem temporarily. We do not know all the chemical reactions…but again cleanliness is key.
133
Conclusions Resin systems and Hevi-Sand
Resin systems
• Discussion about pH, Acid demand and Alkaline demand?
– The September sand has we over acidified, for Furan, it accelerated the reaction initially because of this available acid. In the second phase after the acid had been neutralized, the reaction continues at a normal speed, as with the normal May sand, but still slower than with competition chromite.
– This over acidification is probably just a temporary booster but the reduced test values, compared to competition, does reoccur.
– For PU, the over acidified sand remaining has a negative impact and artificially extends the bench life and stripping time. It appears that it damages the poly-addition process of PU., as the final strength is reduced.
134
Resin systems and Hevi-Sand
Resin systems
• Discussion about pH, Acid demand and Alkaline demand:
What kind of pollution should we look for in our sand? – Dust increasing binder and catalyser need – “Salts” with acid tendency – “Salts” with basic tendency – “Amphotère”? (basic & acid substances)
• Double function to generate acid or basic effects depending on the condition!!
• What should we measure and control? – pH (really not sufficient) – ADV (not enough as we may have “double function substances”) – Also “Alkaline demand” as it should balance the ADV – Various resin systems “bench life” and “strength”
135
Resin systems and Hevi-Sand
Resin systems
• Conclusion Our experience shows that 2 resin systems can really be affected with HEVI-SAND quality variation:
1) FURAN system 2) PolyUrethane (PU) systems cured with liquid amine.
Different reasons can explain it: a) low addition of binders for these kind of process (especially true for PU)
increases weaknesses of our sand (pollution, salts, fines, …) b) pH, acid demand or alkaline demand play a large role in the setting process
(speed and final strength) of this type of binders. - "Acid area" setting for FURAN - "Basic area" setting for PU We can conclude that performance improvement for these systems should
result in improvements for any other system. It is a priority to test resin performance of Hevi-Sand as a control
parameter
Improved Turbidity= Improved Hevi-Sand
• In our Hevi-Sand, Binder Strength and Turbidity have strong relationship
– In our case, the turbidity is associated with insufficient removal of clay like material on the grains resulting in slow set times and lower 24 hour tensile strengths
– Acid Demand value not as a direct relationship as previously thought • can be influenced by claylike material giving elevated ADVs but this can also “hold “
onto residual acid from washing and give low ADV values but poor binder performance (especially in PUNB)
• Relationship not as evident in competition likely because of nature of particles causing turbidity.
– More inactive fines with less clay / buffer like material? – With competition material, we have seen some low turbidity, some high turbidity
and various acid demand values, but usually reasonable binder performance
Extended Turbidity Testing
• Typical turbidity tests didn’t always give us the whole picture as extended mixing always results in higher values
• After plant upgrades, both regular test and extended mixing/washing turbidity values (cake mixer test) were reduced significantly
• Double washing since October has been continuously improving turbidity,
• The recent wet plant upgrades and double washing are resulting in very good turbidity values currently.
Comparison of End Products
Sample NTU 24 hour Furan (psi)
24 Hour PUNB (psi)
R11-0494 July, 2011 single wash 1052 216 109 R12-0037 Jan, 2012 2x wash 387 332 183
R12-0085 Feb, 2012 Production 232 378 270
R11-0568 Competitor ex UK 1048 329 221
Competitor material has high turbidity but good binder properties. It is possible that their turbidity has more inactive fines while our is
more clay / buffer-like particles
Extended Turbidity Testing
January, 2012
Washed Feed
(2 passes)
Feb, 2012 Washed
Feed (1 pass)
Jan, 2012 End Product
Feb, 2012 End Product
Original NTU from standard test
147 135 387 232
1st wash in cake mixer (5 minute mix)
1762 1041 1918 308
2nd wash 1022 548 1118 306 3rd Wash 603 523 615 246 4th Wash 611 394 577 215
Comparison of classifier underflow samples
0
200
400
600
800
1000
1200
1400
1600
1800
2000
Original Turbidity Measurement
1st Wash 2nd Wash 3rd Wash 4th Wash
Turbidity
NTU
Wash number
Turbidity -‐ Mul6ple Washing
Classifer U/F pre upgrade
Classifer U/F aBer upgrade
r on 2nd pass
Comparison of Finished Product Turbidity
, SEM and surface area measurements to confirm
0
500
1000
1500
2000
2500
Original Turbidity Measurement
1st Wash 2nd Wash 3rd Wash 4th Wash
Turbidity
-‐ NTU
Wash
Turbidity-‐Mul6ple washing
Jan end Product
February End Product
Surface Area of Hevi-Sand Sample BET Kr Surface Area
( m2/g) Time frame
Competitor CS -11-005 0.03 July 2011
Hevi Sand Red R11-0415
0.98 July 2011
Hevi Sand Red R12-0085
0.10 Feb 2012
sphere sphere cubic parIcle size 50 100 100 micron S.G. 4.5 4.5 4.5 g/cm^3 surface area per parIcle 7.85E-‐09 3.14E-‐08 6E-‐08 m^2 volume for each parIcle 6.54167E-‐08 5.23333E-‐07 0.000001 cm^3 mass per parIcle 2.94375E-‐07 0.000002355 4.5E-‐06 g number of parIcles/g 3397027.601 424628.4501 222222.2 surface area/g 0.0267 0.0133 0.0133 m^2/g
• Big reduction in our Surface area for February production
Comparison End Products
0
50
100
150
200
250
300
350
400
Sep-‐11 Jan-‐12 12-‐Feb CompeItor
24 hou
r stren
gth -‐psi
Produc6on date
24 hour Tensile Strengths
24 hour Furan Strength
24 hour strength in PUNB
Continued Improvement in Furan Performance
0
50
100
150
200
250
300
350
0
50
100
150
200
250
300
350
400
Strip
Tim
e -‐M
inutes
24 Hou
r Ten
sile Stren
gth -‐psi
Produc6on Date Strength Hour Tensile Strength in Furan
24 hour Tensile Strength
strip Ime (min)
Compe6tor's Strength/ Strip 6me
3x washed
24,5
25
25,5
26
26,5
27
27,5
28
28,5
0:00:00 0:14:24 0:28:48 0:43:12 0:57:36 1:12:00 1:26:24 1:40:48
Tempe
rature C
Time
Time vs. Temperature -‐ 1.0% Furan Binder
Jan-‐12
Feb-‐12
Furan Binder Reaction Time vs. Temperature
Recent production shows a higher peak and higher sustained temperature
Continued Improvement in PUNB Performance
0
5
10
15
20
25
30
35
40
0
50
100
150
200
250
300
R11-‐0415 5/11 9/12 9/22 9/24 10/26 Jan-‐12 Feb-‐12 RY
Strip
Tim
e -‐M
inutes
24 hou
r Ten
sile Stren
gth-‐ psi
Produc6on Date vs. 24 hour tensile strength in PUNB
24 hour tensile strength
Strip Ime
Compe6tor’s Strength/Strip 6me
Acid Demand Test with Organic Acid 0.1 N PTSA
Sample pH ADV @pH3
ADV @ pH 4
ADV @ pH5
R11-0494 single wash 6.74 5.9 3.3 2.8
R12-0037 Jan 2x wash 8.24 6.7 4.9 4
R12-0085 Feb Production
7.99 7.4 4.1 3.6
R11-0568 competitor ex UK
7.56 6.5 4.3 3.8
The data doesn’t show a strong tie between ADV and strength even with organic acid There is definitely some relation between ADV and performance, as extremely high or low ADV will likely affect strength, but it does not appear as closely linked as previously thought.
Typical Acid Demand Test with 0.1 N HCL
Sample pH ADV @pH3
ADV @ pH 4
ADV @ pH5
R11-0494 single wash 6.74 3.4 2.3 1.8
R12-0037 Jan 2x wash 8.24 4.7 3.1 2.7
R12-0085 Feb Production
7.99 5.4 3 2.5
R11-0568 competitor ex UK
7.56 3.9 2.2 1.9
Lower pH value for single wash was likely related to higher acid dosing and incomplete rinsing
Pre Wet Plant Upgrade Samples and Data(Jan 2X Washing)
Sample ID Description Turbidity NTU
pH Bulk Density lbs/ft3 ( kg/m3)
R12-0031 1st Wash Attritioner Feed 415 6.87 178 (2859) R12-0032 1st Wash Attritoner Discharge 374 6.80 179 (2876) R12-0033 1st Wash Classifier U/F 114 6.62 182 (2920) R12-0034 2nd Wash – Attritioner Feed 182 6.98 183 (2931) R12-0035 2nd Wash- Attritioner Discharge 491 7.52 183.5 ( 2939) R12-0036 2nd Wash – Classifier U/F 147 6.99 183 (2932) R12-0037 Jan Production from Double
Washing Process 387 8.24 175 ( 2801)
Post Wet Plant Upgrade Samples and Data(Feb 2012)
Sample ID Description Turbidity NTU
pH Bulk Density lbs/ft3 ( kg/m3)
R12-0074 Primary Attritioner Feed 784 7.33 186 (2975)
R12-0075 Primary Attritioner discharge 948 7.49 181 (2903)
R12-0076 Primary Classifier U/F 373 7.22 183.5 (2939)
R12-0077 Secondary Attritioner feed 178 6.88 186 (2979)
R12-0078 Secondary Attritoner discharge 910 6.97 186.5 (2987)
R12-0079 Secondary Classifier U/F 202 7.32 182.5 (2928)
R12-0080 Bunker Cyclone U/F (wet feed) 135 7.26 183.5 (2939)
R12-0085 End Product from Feb 232 7.99 185 (2963)
Process now “double washes” with a single pass through wet plant this data represents the first Pass through the wet plant R12-0085 is End Product
Decreasing Turbidity- Increasing Bulk Density
Increase in bulk density seen in the February final product
165
170
175
180
185
190
0
100
200
300
400
500
600
700
Sep-‐11 Jan-‐12 12-‐Feb CompeItor
Bulk Den
sity-‐ lbs/N
3
Turbidity
-‐JTU
End Product Turbidity and Bulk Density
Turbidity (JTU)
Bulk Density lbs/B3
Compe6tor’s Turbidity Bulk Density
• Images taken at McCrone Laboratories in Illinois • Images in Backscatter mode
– lighter colours = heavier elements ,such as Cr, darker colours are Lighter elements like Si
• Dark deposits are non-liberated or potentially re-deposited silicate impurities on the surface of the chromite
• February process ( after installation of new equipment) -Appears to be more efficient at deliberating silicates from chromite grains
• February classifier images are after each classifier on the 1st pass through wet plant
• Shows good cleaning after single pass through wet plant • good baseline for comparison to material after dewatering screen • Currently all material will still receive a second trip through wet
plant for maximum cleanliness of end products
SEM Images Support Lab Data
Cleaner Surfaces-SEM Images
• Continued improvement in End Product turbidity seen on SEM of End Products as well
• Upgrades giving us cleaner surfaces than January double wash
Single Wash
2x Wash - January
Plant upgrade Feb 2012
Same Spots – Fewer of Them
• The surface deposits have a similar composition
• Competition still shows some deposits as well
February End Product January End Product
competitor
February Classifier Underflow After 1st UCC February Classifier Underflow After 2nd UCC
February 2012 -Single pass through Wet Plant
January End Product February End Product
End Products
• Increased Attritioning / washing showed-: – Improved performance (strip time, strengths)
which are closely tied to turbidity/ grain cleanliness
• Use of AST’s in the dry process-: - have significanly reduced large silicate particles
• Bulk Density increasing – more fines but hard to see in AFS test due to
sampling difficulty, but clearly reduced turbidity increases flowability and tapped bulk density.
Summary
The research and resultant $5m plant up-
grade has allowed production of ULTRA GRADE Hevi-Sand®.
Q3 2012 will see another step as the de-watering screen and further AST units, cement consistencey into the product.
Summary
What we believed and now can demonstrate to be true
• We believe we now understand more than any company in the field of the impact residuals have on the performance of chromite in foundries.
• We believe the current acceptance standards and test procedures in foundries should change if they need to optimize as cast casting quality through the use of chromite sands
Hevi-Sand® what foundries order
Typical foundry chromite order specifications
Cr% FeO% SiO2% CaO% Turbidity AFS fines LOI PH Acid demand,
ph 3, ph4, ph5
>46% <29% <1% <0.5% <250ppm NA <1% NA <8.5 10ml, 6ml 4ml >45% <29% <1% <0.5% NA 50 <5% NA NA NA
>44% <25% <4% NA NA 42 NA NA NA NA >44% <29% <4% <1.0% <400ppm 50 NA 0.5% NA NA >46% <25% <0.6% <0.4% <150ppm 48-52 <1% 0.1% <8.0 8ml 4.5ml 2.5ml >46% <26% <0.6% <0.4% <250ppm 60-70 <1% 0.1% <8.0 8ml 4.5ml 2.5ml
Hevi-Sand® what foundries order
• These specifications are often historic and based on availability rather than desire
• Foundries have often combined or adjusted specifications
in an attempt to solve consistency problems • Foundries have shorthanded there specifications by not
specifying what test procedures should be used
Typical foundry chromite order specifications
Foundry orders / Testing
• Foundries typically test-: • Chemical analysis, Afs, fines, Ph, Adv, turbidity, LOI.
• They rarely specify any sampling method or test procedure
• The major customer hurdles we have encountered so far which have impacted the project, are order specs which do not reflect what they actually want to receive and testing / test methods which are not standard to the industry.
• We have also had specification requests for material which is not available from any supplier, which foundries have been purchasing for years effectively out of spec.
Hevi-Sand® TESTING
• CHEMICAL ANALYSIS • What most current suppliers define as foundry: +46%Cr, -29% Fe,
-1%silica. Was prior to Hevi-Sand the highest quality material available.
• Most people are testing on expensive XRF equipment which one
would think would produce very good consistent results, the reality is that sample preparation and calibration coupled with correction criteria can produce very different results on the same sample
Hevi-Sand® TESTING
• CHEMICAL ANALYSIS reported at 46.45%Cr same sample differing grinds
Amount retained (g) Screen Size Mesh #1 #2 #3 #4 #5 #6
106 µm No.140 7.32 6.4 4.59 2.69 2.69 1.73 75 µm No.200 1 1.44 1.33 1.4 2 1.76 53 µm No. 270 0.52 0.84 0.85 0.99 1.39 1.53 45 µm No. 325 0.25 0.5 0.52 0.58 0.82 1.05 20 µm No. 635 0.57 1.04 1.14 1.58 2.52 3.41
Pan Pan 0.48 1.11 1.01 1.06 1.53 1.06 total 10.14 11.33 9.44 8.3 10.95 10.54
% passing 200 mesh 17.95 30.80 37.29 50.72 57.17 66.89 XRF Data % Cr2O3 42.988 40.438 41.495 42.663 44.707 45.07 SiO2 0.958 1.913 1.493 1.325 0.572 0.626 FeO 23.748 22.264 22.778 23.538 24.753 24.964 MgO 9.618 9.983 9.556 9.718 9.83 9.895 Al2O3 12.841 12.793 13.408 13.313 14.132 14.341 CaO 0.111 0.111 0.105 0.101 0.092 0.092 Sum 90.264 87.502 88.835 90.658 94.086 94.988
Hevi-Sand® TESTING
• AFS Number: foundry grade typically 45-55afs • The major issues regarding this analysis are use of appropriate sieves
(ASTM sieves vs.. British Standards vs.. ISO sieves) • Grain Fineness is calculation that is intended to be made from
designated series of ASTM sieves (6,12,20,30,40,50,70,100,140,200,270 and pan)
• Percentage retained on each sieve is calculated and multiplied times a set factor for each sieve
• Grain Fineness # = Total (after multiplied respective factor)/ amount collected in the sieve analysis ( usually close to 100 grams or normalized to 100 grams)
• British Standard sieves have a different sieve aperture for a give sieve #; example ASTM 30 mesh = 600 micron; British Standard 30 mesh = 500 micron
• These differences in sieve size can yield different AFS numbers for the same sand if calculated from ASTM vs. British Sieves
Hevi-Sand® TESTING
• AFS Number same sample different sieves The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.
Hevi-Sand® TESTING
• AFS Number
• Because of the factors in the Grain Fineness calculation one can arrive at different results on the same sample
• Therefore it is misleading unless other parameters are specified (i.e. % passing 140 screen, or 80% between 425 and 212 micron etc.) Fines are usually specified because of experiences with fine impurities
• WHAT YOU SEE IS NOT NECESSARILY WHAT YOU GET
Hevi-Sand® TESTING
• Acid demand and PH • These tests are important since variations can
cause problems with acid catalysed binder systems, resulting in loss of properties
• Acid Demand testing involves adding a known
amount of acid to a sample, agitating and letting the sample sit for 1 hour, then titrating with a base to pH 3, 4, and 5 to determine the amount of acid consumed to reach each pH level
Hevi-Sand® TESTING
• Acid Demand and PH
• Typical specifications are 10, 7 and 4 ml for pH 3, 4 and 5 respectively
• Even if in spec large variations in ADV are undesirable
• pH generally should be close to neutral (pH=7) less basic sands generally will have a higher Acid Demand as well
Hevi-Sand® TESTING
• Acid Demand and PH
• What we found in the earlier work shown was that ADV and Ph depend on grain cleanliness, otherwise acid masking can occur which achieves the correct specification requirements but in practice leads to significant problems with binder systems
• What you see is not necessarily what you
get
Hevi-Sand® TESTING
• LOI • Typically there should be no loss on ignition
associated with quality chromite sand if the test is performed in a reducing atmosphere such as Nitrogen
• In the presence of air, the iron oxide transforms and increases in weight
• LOI Test should be carried out in oven with N2 atmosphere or similar.
Hevi-Sand® TESTING
• LOI • The aim of this test is to look for contamination/
impurities that could impact lower the melting/fusion point of the chrome, or impact other thermal properties
• It is included in many QA specification but most
companies cannot test it
Hevi-Sand® TESTING
• LOI Fig 19b: TGA in air (oxidizing environment)
Fig 19a: TGA analysis in Nitrogen Environment
Hevi-Sand® TESTING
• TURBIDITY • A lot of discussion surrounding this test; what do
the results mean, how it should be tested • Turbidity is a measure of light scatter caused by
suspended solids in a liquid sample. • Turbidity in Chromite, is generally attributed to
low melting point accessory silicate mineral phases
• High turbidity is thought to contribute to certain types of foundry defects such as double skin, and in can contribute to higher SiO2 levels
Hevi-Sand® TESTING
• TURBIDITY • Jackson Turbidity test has been the industry
standard, measured in ppm of silica or Jackson Turbidity Units (JTU) this test compares the visual turbidity of a sample to a reference sample of known ppm silica
• Measures the scattering of light by the amount of
time required to obscure a standard candle flame under the testing cylinder
Hevi-Sand® TESTING
• TURBIDITY
• Drawbacks with Jackson method include variability of calibration curves, standards and operators
• Each tube is supposed to be custom calibrated by users based on solutions prepared from diatomaceous earth
• Candle light flame as a light source has limitations in examining low turbidity samples, samples with very fine suspended solids and samples with color or bright surroundings.
Hevi-Sand® TESTING
• Modern instrument (Nephelometer) makes use of fixed angle light source, at a fixed wavelength and modern Formazin based standards to determine turbidity, typically specified in most other turbidity testing applications (waste water, brewing etc)
• Formazin Standards are traceable, certified and
reproducible, not all turbidity standards are true Formazin, but all are traceable to Formazin reference standards
Hevi-Sand® TESTING
• Modern Nephelometers report in a variety of interchangeable units all related to Formazin Standards the most common being NTU, FTU or FAU,
• NTU and JTU or ppm are not equivalent and there is no consensus on correlation or conversion factors (typically JTU x 2)
• Not all Turbidity meters (Nephelometers) are the same, many only employ a single 90 degree detector for analyzing turbidity, this works well for low turbidity samples like drinking water, but may require dilution for higher turbidity samples, most portable turbidity meters are of this variety
Hevi-Sand® TESTING
• Other turbidity meters employ additional detectors to extend the calibration range and overcome color effects in the sample
• These type of meters appear to be most suitable for analyzing chromite sands
• Amcol uses this type of turbidity meter
Hevi-Sand® TESTING
Turbidity Meters
Hevi-Sand® TESTING
• Every method requires agitation and traditionally this is done by shaking sample by hand in sealed jar or beaker
• Variation in results observed depending on how long and by whom the sample was Shaken
• 12 different individuals were asked to perform the test, using the same equipment and method, high was 739 NTU, low was 378 NTU
Hevi-Sand® TESTING
• The variability demonstrated a need to standardize the shaking process
• Several things were tried, shaking table, magnetic stir bar/ stir plate, rotation/ tumbling, wrist action shaker
• It was observed during this testing that increased agitation time yielded higher turbidity values, values still increasing at 30 minutes of agitation
• This brings up the issue of are we concerned about total turbidity or only what can be generated in short amount of time?
• What is more realistic in a foundry setting?
Hevi-Sand® TESTING
• From a testing perspective it is unreasonable to have a 30 minute test, so 1 minute agitation was chosen using the wrist action shaker because the results were thought to reasonable compared to shaking method and the reproducibility
• The 12 individuals were asked to repeat the test with the wrist action shaker
• Low result was 434 NTU and the high was 512, a much closer grouping of results
• A new proposed method includes the use of the Hach 2100 N turbidity meter and the wrist action shaker
• A complete procedure and data regarding this turbidity testing appears in our HS tech paper
Hevi-Sand® TESTING
• Where we are now. • Completing a tech paper which reappraises foundry
sand testing procedures and acceptance specifications.
• We believe the industries institutes should evaluate these findings and try to standardize there recommendations.
Ultra Grade Hevi-Sand®
• Where we are now.
Ultra Grade Hevi-Sand®
• Where we are now.
Ultra Grade Hevi-Sand®
• Where we are now.
Ultra Grade Hevi-Sand®
• Where we are now.
Ultra Grade Hevi-Sand®
• Where we are now.
Ultra Grade Hevi-Sand®
• Where we are now.
Hevi-Sand® What it means for your Foundry
To Maximize foundry performance
We must understand what foundry problems are and there likely causes
• .
Hevi-Sand® What it means for your Foundry
Our Product Strategy
To Allow foundries to make castings like these consistently
.
Hevi-Sand® What it means for your Foundry
Hevi-Sand® What it means for your Foundry
Hevi-Sand® What it means for your Foundry
Poor Quality What it means for your Foundry
Our Product Strategy
Help avoid making castings like these. .
Double skin defects
Double skin defects
Double skin defects
Double skin defects
Double skin defects
Double skin defects
• High impurity levels • High acid demand • High fines • High binder levels • Long pouring times • High pouring
temperatures.
Double skin defects
• Click icon for Double Skin Information
• But also check Silicates content of chromite • Is your mixer feed hopper clean or full of low
melting point magnesium silicate dust • Are you adding excess resin and catalyst to
compensate for variable sand quality • Do you have a segregation problem. • Do you have a thick enough, consistent thickness
layer of chromite.
Document
Other defects BURN IN / FUSION
• .
Other defects Poor Surface Finish / Overheating
• .
Defect Poor Surface Finish / Overheating / Fusion
• .
• What’s in your sand, is it thick enough.
• Are you moulding correctly.
• christmas tree effect.
• Veins
Hevi-sand® Technical FoundrySolutions
• .
• Large reduction in low melting point silicates, (increased fusion temperature, improved heat abstraction)
• Improved grain cleanliness, (less dust generation in feed hoppers, improved performance binder stability)
• ADV / PH controlled in-line against foundry resins not data sheets ( reduced additions of resin + Catalyst more predictable set and strip times, less gas generation)
• Sized to your casting requirements, (permeability and packing density control)
• Segregation control, (in-line testing ensures what’s on the bag is in the bag)
• A global team of Foundry Trained Sales Engineers to visit your Foundry
Hevi-Sand® Benefits • Your Foundry Benefits
• Global Consistent brand “Hevi-Sand®”
• Unique value of “Mine to Customer”, “Face to Face”
• Ultra grade tailor made product “Hevi-sand®”
• Onsite technical advise, service and support
• Continuity of supply with local stocking points.
• Price stability.
• Interactive website, plant visits
• A large in house lab and research facility at your service
Hevi-Sand® other Markets
• Nozzle Sand or Well Filler
Sliding Gate Design
Sliding plate
α
Well block
1 A well block is incorporated into the ladle lining above the
sliding gate
2 Before the steel is tapped into the ladle the
well is filled with refractory sand to
protect the sliding plate
3 When the slide is opened the filler material should flow out
allowing the steel to pass through the nozzle
Well filler performance
Thickness & strength Depends on : • chemistry filler • chemistry steel • time • temperature • grain size distribution Sliding plate
α Sintered layer
Well filler
homogeneity Depends on : • flow ability • water content • grain size distribution • segregation
Infiltration of slag Depends on : • cleaning of ladle • cleaning of nozzle/well block • quality of well block • time/temp heating facilities • viscosity of slag
Penetration/interaction of steel Depends on : • chemistry filler • chemistry steel • Steel pressure • Pore size distribution of filler • Amount of sintering filler
Depends on :sintered layer/ steel penetration/well filer/slag infiltration diameter of nozzleshape of well block quality of the filling of the well block = α Opening rate
Well block
1% change in opening can save a plant
120,000tons of steel a year
Oxygen Lancing To Open Gate
Website is now up and running at www.hevi-
sand.com
Hevi-Sand® Global Team
Hevi-Sand®
• It has been stressful and caused premature hair loss for some.
Hevi-Sand®
• It has been even more stressful for others.
Hevi-Sand®
• But not for everyone.
Why Hevi-Sand®
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