Chemical Name: Calcium sulphate hemihydrate
Alpha Gypsum is obtained by heating of gypsum stone under high pressure and Alpha Gypsum is chemically same with CaSO4.1 / 2H2O formula and beta gypsum but different from in the point of crystal structure.
Structure of beta gypsum is needle-like and amorphous while crystal structure of Alpha Gypsum is geometric.
It shows that Alpha Gypsum as compare to beta gypsum appears to be fluidized when mixed with much less water than beta gypsum and Alpha Gypsum offers high strength properties.
Alpha Gypsum is preferred in different industrial applications by virtue of high mechanical strength.
Alpha gypsum is a common ingredient for making plaster.
Alpha gypsum is made by processing gypsum stone into a fine powder and is well regarded for its strength and low absorptive levels.
Application Areas of Alpha Gypsum:
-Ceramic Molding Plaster
-Dental Plaster
-Screed Binder
-Construction Chemicals
-Orthopedic Plaster
-Architectural and Decorative Adornments
How Alpha Gypsum's Made:
Alpha gypsum is made by calcining gypsum stone under high pressure.
Calcination is a process that drives out the moisture in a substance by heating it to a specific temperature.
Uses of Alpha Gypsum:
Alpha gypsum is essentially used whenever more strength is needed, as alpha gypsum will harden to a degree that is much greater than normal plaster.
DIFFERENT USAGES OF ALPHA GYPSUM:
1. α gypsum powder high-strength gypsum is suitable for high-strength plastering projects, decorative products and gypsum board.
Alpha Gypsum can be used in a high humidity environment after mixed with water repellent.
Alpha Gypsum is made into a non-shrinking adhesive with the organic cementing agent.
Organic materials, such as polyvinyl chloride alcohol aqueous solution and polyvinyl acetate emulsion, can be formulated as cementing agents.
Alpha Gypsum is suitable for GRG, DIY plaster products, craft jewellery and various precision mould making.
2.β gypsum powder building is mixed with water and retarder to synthesize gypsum slurry, which can be used as indoor paint.
Indoor plastering and stuccoing building gypsum mixed with water, sand and retarder to synthesize gypsum mortar used for indoor plastering.
The plastered surface is smooth, delicate, white and beautiful.
Gypsum mortar can also be used as a primer for paint, etc., and can be directly painted or pasted on wall coverings or wallpaper.
Water:
To make plaster out of alpha gypsum you need to add roughly 22 to 45 pounds of water per every 100 pounds of alpha gypsum and then stir.
After Drying:
One of the negative side effects of working with alpha gypsum is that once Alpha Gypsum dries, it can usually not be carved or molded as normal plaster can be.
This is due to Alpha Gypsums increased hardness.
Increasing Strength:
Other forms of plaster can be added to alpha gypsum, such as beta gypsum, to increase the strength of the plaster even more.
What is Gypsum?
Gypsum is a naturally occurring mineral mined from deposits formed by ancient seabeds as a raw material.
Composed of calcium sulfate and water, it is used for a variety of manufacturing, industrial, and agricultural uses.
An important property of gypsum is that it is naturally fire-resistant.
How Cement is Made?
Cement is produced from a chemical combination of calcium, silicon, aluminum, iron and small amounts of other ingredients that are carefully measured to get the right result.
Often gypsum is added during the final grinding process since it helps regulate how long the concrete takes to set.
Cement is fine in texture and one pound of cement contains 150 billion grains.
Mixing Cement and Gypsum:
You can use a pre-mixed product combining the cement ingredients with the right amount of gypsum.
You can also mix them yourself.
As soon as you add water to the mix, the hardening process begins.
The first part of this process is called the dormant period, and lasts up to halfway through the drying process.
This is when concrete can be placed into forms.
The paste soon will become too stiff to work with.
Uses of Pre-Mixed Gypsum and Cement:
Gypsum cements possess considerably greater strength and hardness than standard industrial plasters.
Also, gypsum cements require less water for mixing and the casts they produce are easier to paint, heavier, less porous, and more durable.
These cements produce more heat while setting.
Given these properties, gypsum cements are often used to make statuary and other art objects like lamp bases and craft projects.
DEFINITION of Alpha gypsum:
ALPHA GYPSUM is a common ingredient for making plaster.
Alpha gypsum is made by processing gypsum stone into a fine powder and is well regarded for its strength and low absorptive levels.
DIFFERENCE PHYSICAL PROPERTIES of Alpha gypsum:
1.Hemihydrate gypsum has two forms: α and β, both of which are rhombic crystals, but their physical properties are different. α-type hemihydrate gypsum has good crystallinity and firmness.
β-type hemihydrate gypsum is a flaky and cracked crystal with excellent crystals.
Alpha gypsums specific surface area is much larger than that of α-type hemihydrate gypsum.
When producing gypsum products, α-type semi-hydrated gypsum requires less water than β-type, and the products have higher compactness and strength.
2. With the continuous progress of hydration, β-type hemihydrate gypsum produces more and more colloidal particles of dihydrate gypsum.
These particles are smaller than the original, have a large specific surface area, and absorb a lot of water; they continue to be hydrated and evaporated.
Decrease, the consistency of the slurry continues to increase, the adhesion between colloidal particles is gradually strengthened, friction and adhesion between the particles are generated, and the slurry gradually loses its plasticity and gradually condenses.
DIFFERENT PRODUCTION PROCESSES of Alpha gypsum:
Typically, α-type hemihydrate gypsum, also known as high-strength gypsum, is steamed in a saturated steam medium.
The β-type hemihydrate gypsum, which is also construction gypsum, is calcined with a wok or an open device in a rotary kiln.
Safety Tips:
Whether working on a construction site or laying a patio for your backyard, some basic protections is needed.
Safety glasses or goggles help keep the fine dust from blowing into your eyes.
Cement is alkaline in nature, so wet caustic concrete and other cement mixtures are harmful to skin.
Protective clothing like long pants, long sleeves and waterproof gloves is necessary.
How do you make the best use of alpha gypsum for all your modelling and building needs?
You simply rely on us at Dalchem - the industry-leading supplier of all moulding, casting and artistic needs.
Relying on the industry leaders:
Here’s a short guide on why you need to take advantage of our knowledge, expertise and experience; We are an acknowledged world leader in supplying up-to-date technologies related to effective applications of alpha gypsum.
Expert advice guides home-based hobbyists and commercial engineers on proper material selections and how to apply them to the work at hand.
Website reliability:
Our website’s drop-down menus are easy to navigate.
Instructions and knowledge-based guides on what alpha gypsum entails is written professionally with the layman in mind.
Alpha gypsum advantages:
There are, of course, many advantages to using alpha gypsum.
Alpha gypsum, better known as gypsum plaster, is a homogenous substance which means that after being properly mixed it is transformed into a solid substance free of grain, soft or hard spots, or lumps.
Alpha gypsums paste wax is effective for home renovations or restorations.
Correctly prepared paste wax is used to restore old wood.
No less than eight industries, including those of artists and home decorators, use this versatile product’s flexible RTV silicone rubber moulds.
Gypsum plaster is poured easily into most moulds, and we also have our own system for use with other moulds and casting.
Effective product use:
From the layman’s perspective, not all processes and methodologies are cast in stone.
In our How-To guide, we take time explaining the finer points. Here are a few examples:
For the artist, Dalchem Chromatic Alginate is recommended. It is a special moulding gypsum known by its technical term: hydrostone.
For preparing a good paste wax, use a clean, soft cotton cloth to apply the wax to a finished piece.
When applying paste wax to a finished piece, apply the cloth onto the surface of the product. This allows the wax to seep into the piece.
Preparing a casting medium is not difficult when supplier’s instructions are followed correctly. Proper pouring into latex moulds ensures no trapping of bubbles in the liquid. Setting time and plasticity periods are two important points to consider.
Setting time begins with adding gypsum plaster to water. Plasticity is dependent on the type of gypsum plaster being used.
An improved "lump" process for producing alpha gypsum, calcium sulfate hemihydrate, from natural gypsum rock of the type wherein lumps of gypsum rock particles (a minimum of about 1/2 inch or 1.3 cm. in size) are calcined to low water-demand alpha hemihydrate by autoclaving in a saturated steam atmosphere, quickly dried and pulverized is disclosed.
The improvement allows the thorough processing of natural gypsum as large sized particles or containing considerable selenite and includes the steps of initiating calcination without crystal habit modifier and, after hemihydrate formation has commenced, adding crystal habit modifier and completing calcination under increased steam pressure.
In this study, a new type of fly ash binder has been developed using fly ash, hydrated lime sludge and Portland cement, as well as α-gypsum plaster as stimulator.
The hydration process and microstructure of the fly ash binder was investigated with differential thermal analysis, X-ray diffraction and scanning electron microscopy.
These studies showed that the strength development of binder takes place through formation of ettringite and tobermorite.
The durability of fly ash binder was assessed by its performance in water by immersion and by alternate wetting and drying cycles at 27–50 °C.
The results reveal absence of leaching of the matrix in fly ash binder as well as reduction in strength and enhancement in weight loss with the increase in temperature and cycles.
The fly ash binder is found suitable for use in masonry mortars, concrete and bricks.
The final product density of gypsum and consequently its resistance to bending, compression and scratching increases.
Compression strength of the final product, made of 4-consistency gypsum in which 100 grams of gypsum is mixed with 25 grams of water, is around 900 kg / cm².
Considering that this figure is around 300 kg / cm² in a normal reinforced concrete, it becomes easier to understand the importance of the strengths achieved with Alpha Gypsum.
If the gypsum / water ratio is 5, the compressive strength will increase up to 1100 kg / cm².
It is possible to produce a product with a gypsum / water ratio of 1-1.5, but only with Beta Gypsum and a product of 1.5-5.0 proportions, and only with Alfa Gypsum produced with special technology.
Alpha Gypsum is obtained by heating gypsum under high pressure and is chemically the same with the formula CaSO4.1/2H2O and beta gypsum but different at the point of crystal structure.
KEYWORDS:
10101-41-4, 13397-24-5, Calcium sulphate hemihydrate, Phosphogypsum, Landplaster, GIPS, Gypsum (Ca(SO4).2H2O), UNII-4846Q921YM, Sulfuric acid calcium(2+) salt dihydrate, MFCD00149625
TECHNICAL SPECIFICATIONS:
Water / Plaster Ratio (%): 38 - 42
Hemihrate Content (%): > 90
Socket Start (min): > 3
End of Setting (min): <25
Spreading Diameter (mm): 160 - 220
Crystal Water (%): 5.8 - 6.2
Compressive Strength (kg / cm2): > 400
Bulk Density (g / L): 1100
Alpha gypsum is produced in different finenesses according to demand.
Features of Alpha gypsum:
- Easy to use and can be cast solid, laid up by hand with chopped fiber or sprayed. Fully cured pieces can be painted, sanded, machined and polished.
- Used to make lightweight pieces that are very strong and water-resistant.
- Applications include making architectural elements, reproducing sculpture and special effects.
- Vibrant colors are possible by adding pigments.
- Metal powders (bronze, pewter, brass, etc.) can be added to give the look of real metal castings at a fraction of the cost.
- You can duplicate the look of marble or ceramic by adding inexpensive fillers.
- When used with United States FGR 95 Alpha Gypsum, Matrix™-G has received a flame rating of UL-94V-O and meets
GYPSUM
Gypsum is an essential raw material for the development of all plaster based products.
Gypsum is generally a matt white finely crystalline rock.
Gypsums purity and homogeneity play a vital role in the quality of plaster based products.
Alphaplatre offers industrial solutions for handling and storing gypsum, thus enabling its homogenisation.
This intermediate step is essential to obtain a more regular and constant gypsum.
Generally a buffer stock of 5 to 15 days is created and reclaimed later.
In order to guarantee the quality of this operation Alphaplatre offers 2 solutions, detailed below:
Stacker:
Stackers are directly connected to the belt conveyors ensuring the gypsum supply.
The stackers can be mobile and installed on rails or wheels.
They perform a precise storage enabling the homogenisation of gypsum.
This equipment can adjust its height to reduce the risk of falling product.
Tripper:
Directly integrated to the structure of the storage warehouse, the tripper is mobile all along the building.
The assembly is fixed to a conveyor belt which ensures the gypsum supply.
The gypsum is then distributed on each side of the conveyor for storage.
The movements of the tripper are automated and ensure a perfect homogenisation of the product.
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O.
Gypsum is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywall.
A massive fine-grained white or lightly tinted variety of gypsum, called alabaster, has been used for sculpture by many cultures including Ancient Egypt, Mesopotamia, Ancient Rome, the Byzantine Empire, and the Nottingham alabasters of Medieval England.
Gypsum also crystallizes as translucent crystals of selenite.
Gypsum forms as an evaporite mineral and as a hydration product of anhydrite.
Gypsum is used in a wide variety of applications:
Construction industry:
Gypsum board is primarily used as a finish for walls and ceilings, and is known in construction as plasterboard, sheet rock, or drywall.
Gypsum blocks are used like concrete blocks in building construction.
Gypsum mortar is an ancient mortar used in building construction.
A component of Portland cement used to prevent flash setting (too rapid hardening) of concrete.
Agriculture:
Fertilizer: In the late 18th and early 19th centuries, Nova Scotia gypsum, often referred to as plaster, was a highly sought fertilizer for wheat fields in the United States.
Gypsum provides two of the secondary plant macronutrients, calcium and sulfur.
Unlike limestone, it generally does not affect soil pH.
Reclamation of saline soils, regardless of pH.
When gypsum is added to sodic (saline) and acidic soil, the highly soluble form of boron (sodium metaborate) is converted to the less soluble calcium metaborate.
Exchangeable sodium percentage is also reduced by gypsum application.
The Zuiderzee Works uses gypsum for the recovered land.
Other soil conditioner uses: Gypsum reduces aluminium and boron toxicity in acidic soils.
Gypsum also improves soil structure, improving water absorption and aeration.
A wood substitute in the ancient world: For example, when wood became scarce due to deforestation on Bronze Age Crete, gypsum was employed in building construction at locations where wood was previously used.
Soil water potential monitoring: a gypsum block can be inserted into soil, its electrical resistance measured to derive soil moisture.
Modeling, sculpture and art:
Plaster for casting moulds and modeling.
As alabaster, a material for sculpture, it was used especially in the ancient world before steel was developed, when its relative softness made it much easier to carve.
During the Middle Ages and Renaissance, it was preferred even to marble.
In the medieval period, scribes and illuminators used it as an ingredient in gesso, which was applied to illuminated letters and gilded with gold in illuminated manuscripts.
Food and drink:
A tofu (soy bean curd) coagulant, making it ultimately a significant source of dietary calcium.
Adding hardness to water used for brewing.
Used in baking as a dough conditioner, reducing stickiness, and as a baked-goods source of dietary calcium.
The primary component of mineral yeast food.
Used in mushroom cultivation to stop grains from clumping together.
Medicine and cosmetics:
Plaster for surgical splints.
Impression plasters in dentistry.
Other:
An alternative to iron oxide in some thermite mixes.
Tests have shown that gypsum can be used to remove pollutants such as lead or arsenic from contaminated waters.
Etymology and history:
The word gypsum is derived from the Greek word γύψος (gypsos), "plaster".
Because the quarries of the Montmartre district of Paris have long furnished burnt gypsum (calcined gypsum) used for various purposes, this dehydrated gypsum became known as plaster of Paris.
Upon adding water, after a few dozen minutes, plaster of Paris becomes regular gypsum (dihydrate) again, causing the material to harden or "set" in ways that are useful for casting and construction.
Gypsum was known in Old English as spærstān, "spear stone", referring to its crystalline projections.
In the mid-18th century, the German clergyman and agriculturalist Johann Friderich Mayer investigated and publicized gypsum's use as a fertilizer.
Gypsum may act as a source of sulfur for plant growth, and in the early 19th century, it was regarded as an almost miraculous fertilizer.
American farmers were so anxious to acquire it that a lively smuggling trade with Nova Scotia evolved, resulting in the so-called "Plaster War" of 1820.
Physical properties:
Gypsum is moderately water-soluble (~2.0–2.5 g/l at 25 °C) and, in contrast to most other salts, it exhibits retrograde solubility, becoming less soluble at higher temperatures.
When gypsum is heated in air it loses water and converts first to calcium sulfate hemihydrate, (bassanite, often simply called "plaster") and, if heated further, to anhydrous calcium sulfate (anhydrite).
As with anhydrite, the solubility of gypsum in saline solutions and in brines is also strongly dependent on NaCl (common table salt) concentration.
The structure of gypsum consists of layers of calcium (Ca2+) and sulfate (SO2−4) ions tightly bound together.
These layers are bonded by sheets of anion water molecules via weaker hydrogen bonding, which gives the crystal perfect cleavage along the sheets (in the {010} plane).
The Mohs scale of mineral hardness defines gypsum as hardness value 2 based on scratch hardness comparison.
Crystal varieties:
Main article: Selenite (mineral)
Gypsum occurs in nature as flattened and often twinned crystals, and transparent, cleavable masses called selenite.
Selenite contains no significant selenium; rather, both substances were named for the ancient Greek word for the Moon.
Selenite may also occur in a silky, fibrous form, in which case it is commonly called "satin spar".
Finally, it may also be granular or quite compact. In hand-sized samples, it can be anywhere from transparent to opaque.
A very fine-grained white or lightly tinted variety of gypsum, called alabaster, is prized for ornamental work of various sorts.
In arid areas, gypsum can occur in a flower-like form, typically opaque, with embedded sand grains called desert rose.
Gypsum also forms some of the largest crystals found in nature, up to 12 m (39 ft) long, in the form of selenite.
Occurrence:
Gypsum is a common mineral, with thick and extensive evaporite beds in association with sedimentary rocks.
Deposits are known to occur in strata from as far back as the Archaean eon.
Gypsum is deposited from lake and sea water, as well as in hot springs, from volcanic vapors, and sulfate solutions in veins.
Hydrothermal anhydrite in veins is commonly hydrated to gypsum by groundwater in near-surface exposures.
Gypsum is often associated with the minerals halite and sulfur. Gypsum is the most common sulfate mineral.
Pure gypsum is white, but other substances found as impurities may give a wide range of colors to local deposits.
Because gypsum dissolves over time in water, gypsum is rarely found in the form of sand.
However, the unique conditions of the White Sands National Park in the US state of New Mexico have created a 710 km2 (270 sq mi) expanse of white gypsum sand, enough to supply the US construction industry with drywall for 1,000 years.
Commercial exploitation of the area, strongly opposed by area residents, was permanently prevented in 1933 when President Herbert Hoover declared the gypsum dunes a protected national monument.
Gypsum is also formed as a by-product of sulfide oxidation, amongst others by pyrite oxidation, when the sulfuric acid generated reacts with calcium carbonate.
Its presence indicates oxidizing conditions. Under reducing conditions, the sulfates it contains can be reduced back to sulfide by sulfate-reducing bacteria.
This can lead to accumulation of elemental sulfur in oil-bearing formations, such as salt domes, where it can be mined using the Frasch process Electric power stations burning coal with flue gas desulfurization produce large quantities of gypsum as a byproduct from the scrubbers.
Orbital pictures from the Mars Reconnaissance Orbiter (MRO) have indicated the existence of gypsum dunes in the northern polar region of Mars, which were later confirmed at ground level by the Mars Exploration Rover (MER) Opportunity.
Mining:
Commercial quantities of gypsum are found in the cities of Araripina and Grajaú in Brazil; in Pakistan, Jamaica, Iran (world's second largest producer), Thailand, Spain (the main producer in Europe), Germany, Italy, England, Ireland, Canada and the United States.
Large open pit quarries are located in many places including Fort Dodge, Iowa, which sits on one of the largest deposits of gypsum in the world, and Plaster City, California, United States, and East Kutai, Kalimantan, Indonesia.
Several small mines also exist in places such as Kalannie in Western Australia, where gypsum is sold to private buyers for additions of calcium and sulfur as well as reduction of aluminum toxicities on soil for agricultural purposes.
Crystals of gypsum up to 11 m (36 ft) long have been found in the caves of the Naica Mine of Chihuahua, Mexico.
The crystals thrived in the cave's extremely rare and stable natural environment.
Temperatures stayed at 58 °C (136 °F), and the cave was filled with mineral-rich water that drove the crystals' growth.
The largest of those crystals weighs 55 tonnes (61 short tons) and is around 500,000 years old.
Synthesis:
Synthetic gypsum is produced as a waste product or by-product in a range of industrial processes.
Desulfurization:
Flue gas desulfurization gypsum (FGDG) is recovered at some coal-fired power plants.
The main contaminants are Mg, K, Cl, F, B, Al, Fe, Si, and Se. They come both from the limestone used in desulfurization and from the coal burned.
Gypsum is pure enough to replace natural gypsum in a wide variety of fields including drywalls, water treatment, and cement set retarder.
Improvements in flue gas desulfurization have greatly reduced the amount of toxic elements present.
Desalination:
Gypsum precipitates onto brackish water membranes, a phenomenon known as mineral salt scaling, such as during brackish water desalination of water with high concentrations of calcium and sulfate.
Scaling decreases membrane life and productivity.
This is one of the main obstacles in brackish water membrane desalination processes, such as reverse osmosis or nanofiltration.
Other forms of scaling, such as calcite scaling, depending on the water source, can also be important considerations in distillation, as well as in heat exchangers, where either the salt solubility or concentration can change rapidly.
A new study has suggested that the formation of gypsum starts as tiny crystals of a mineral called bassanite (CaSO4·0.5H2O).
This process occurs via a three-stage pathway:
homogeneous nucleation of nanocrystalline bassanite;
self-assembly of bassanite into aggregates, and
transformation of bassanite into gypsum.
Refinery waste
The production of phosphate fertilizers requires breaking down calcium-containing phosphate rock with acid, producing calcium sulfate waste known as phosphogypsum (PG).
This form of gypsum is contaminated by impurities found in the rock, namely fluoride, silica, radioactive elements such as radium, and heavy metal elements such as cadmium.
Similarly, production of titanium dioxide produces titanium gypsum (TG) due to neutralization of excess acid with lime.
The product is contaminated with silica, fluorides, organic matters, and alkalis.
Impurities in refinery gypsum waste have, in many cases, prevented them from being used as normal gypsum in fields such as construction.
As a result, waste gypsum is stored in stacks indefinitely, with significant risk of leaching their contaminants into water and soil.
To reduce the accumulation and ultimately clear out these stacks, research is underway to find more applications for such waste products.
Occupational safety:
People can be exposed to gypsum in the workplace by breathing it in, skin contact, and eye contact.
Calcium sulfate per se is nontoxic and is even approved as a food additive, but as powdered gypsum, it can irritate skin and mucous membranes.
United States:
The Occupational Safety and Health Administration (OSHA) has set the legal limit (permissible exposure limit) for gypsum exposure in the workplace as TWA 15 mg/m3 for total exposure and TWA 5 mg/m3 for respiratory exposure over an 8-hour workday.
The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of TWA 10 mg/m3 for total exposure and TWA 5 mg/m3 for respiratory exposure over an 8-hour workday.
Physical Properties of Alpha Gypsum:
Water / plaster ratio (%) : 38-42
Hemihydrate content (%) : >90
Initial setting time (min.) : 3-8
Final setting time (min.): 10-25
Slump diameter (mm): 160-200
Crystal water (%): 5,5-6,2
Compressive strength (kg/cm2): >400
Bulk density (g/L): 1100±100
Degree of whiteness (*L) : >95
Dv(90) (micrometer) (Malvern particle Sizer): 55-65
Calcium sulfate dihydrate
10101-41-4
Phosphogypsum
Landplaster
GIPS
Gypsum (Ca(SO4).2H2O)
13397-24-5
calcium;sulfate;dihydrate
Sulfuric acid, calcium salt (1:1), dihydrate
UNII-4846Q921YM
Sulfuric acid, calcium(2+) salt, dihydrate
MFCD00149625
Sulfuric acid, calcium salt, hydrate (1:1:2)
Calcium(II) sulfate, dihydrate (1:1:2)
4846Q921YM
Annaline
Compactrol
Gypsite
Primoplast
Gypsum stone
Duracal Cemen
Magnesia White
Tiger Kencoat
Crystacal R
CoCoat T
G 6 (refractory)
SK (mineral)
G 75 (mineral)
G 16 (gypsum)
Calcium sulfate, dihydrate
PE 20A
Calcium sulfate dihydrate (CaSO4.2H2O)
land plaster
C.I. 77231
CaSO4-2H2O
CaSO4.2H2O
Ca.SO4.2H2O
calcium sulfate--water (1/2)
DTXSID7047514
CHEBI:32583
Calcium sulfate dihydrate, reagent
Calcium sulfate dihydrate ACS grade
8210AF
AKOS015903950
FT-0623414
J-000304
Q30135771
UNII-WAT0DDB505 component PASHVRUKOFIRIK-UHFFFAOYSA-L