calcium sulfate

[′kal·se·əm ′səl‚fāt]

(inorganic chemistry)

CaSO₄ A white crystalline salt, insoluble in water; used in Keene's cement, in pigments, as a paper filler, and as a drying agent.

Either of two hydrated forms of the salt: the dihydrate, CaSO₄·2H₂O, and the hemihydrate, CaSO₄·½H₂O.

calcium sulfate

Anhydrite or gypsum dihydrate which has been calcined to the point at which all the water of crystallization has been removed.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Calcium Sulfate

CaSO₄, a salt, existing in nature as the dihydrate CaSO₄-2H₂O (gypsum, selenite) and in an anhydrous state (anhydrite). Anhydrous calcium sulfate occurs in the form of colorless crystals with a density of 2.96 g/cm³ and a melting point of 1450°C. It combines very slowly with water, exhibiting a poor solubility of 0.2036 g per 100 g H₂O at 20°C and 0.067 g at 100°C. The half-hydrate CaSO₄-1/2 H₂O is known; when mixed with water, it hardens rapidly, converting into CaSO_4««2H₂O. Calcium sulfate is used in the manufacture of figures and casts, as a construction material, and in medicine.

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References in periodicals archive

The highest values of relative height / growth (Figure 2A) and diameter (Figure 2B) of the plant species were obtained by applying elemental sulfur or calcium sulfate. It was observed that the species Amburana cearensis was the most sensitive to salinity in relation to the relative growth in height (Figure 1A), especially in the treatment with organic matter.

Initial growth of tree species grown on salinized soil with conditioners

Calcium sulfate: Properties and clinical applications.

Effects of Calcium Sulfate Combined with Platelet-rich Plasma on Restoration of Long Bone Defect in Rabbits

Calcium sulfate (CaS[O.sub.4]) was applied without incorporation in total area about 30 days before planting.

Fuentes de azufre sobre el control de Scaptocoris castanea (Hemiptera: Cydnidae) en algodon

The work in Siilinjarvi will increase Kemira's capacity for producing calcium sulfate pigments by 25,000 tons to 175,000 tons.

Kemira Oyj increases production of calcium sulfate pigments in Finland

With the exception of a mild inflammatory reaction to bovine collagen in some patients and inflammation sometimes seen during the first few weeks after calcium sulfate insertion, these biomaterials are not usually associated with significant inflammation, so acute inflammation associated with one of these materials should raise the suspicion of ongoing infection.

An overview of the histology of skeletal substitute materials

The introduction of calcium sulfate and calcium phosphate cements is a recent advance in this field.

Osteobiologics

The authors found that the WTC P[M.sub.2.5] samples were alkaline and composed primarily of calcium-based compounds such as calcium sulfate (gypsum) and calcium carbonate (calcite).

World Trade Center fine particulate matter--chemistry and toxic respiratory effects: an overview. (World Trade Center: mini-monograph)

Numerous needles of calcium sulfate dihydrate reaction product are present in the hydrated systems.

The Visible Cement Data Set

"Ginseng likes a lot of calcium," Hankins said, "but in the form of gypsum, which is calcium sulfate, not carbonate.

Gold in the Woods

Age (years) Amount (mg per day) 1 to 3 500 4 to 8 800 9 to 18 1,300 Sources of Calcium Dairy Milk (1 cup) 300 mg Cheese (1 ounce) 175-275 mg Cottage cheese (1 cup) 140 mg Yogurt (1 cup, low fat/nonfat) 415 mg Yogurt (1 cup, low fat fruited) 315 mg Ice Cream (1 cup) 150 mg Ice Milk (1 cup) 150 mg Frozen Yogurt (1 cup) 200 mg Pudding or Custard (1 cup) 300 mg Other Sources Calcium enriched orange juice (1 cup) 300 mg Tofu (with calcium sulfate 1 cup) 850 mg Sardines/Salmon (with bones, 3 ounces) 250 mg Perch (baked, 3 ounces) 117 mg Broccoli (fresh or cooked, 1 cup) 240 mg Almonds (1 cup) 384 mg Greens (turnip & beet, 1 cup) 150 mg Okra (1 cup) 150mg Beans (red, pinto, etc.

Calcium Intake Guidelines