Calcium Sulfate CAS 7778-18-9
Application Scenarios:
Industrial Grade
1. Building Gypsum and Wall Materials (Cooked Gypsum Core): Raw gypsum is heated and dehydrated to produce cooked gypsum (hemihydrate gypsum). After mixing with water, it can quickly re-harden. It is widely used in the manufacture of gypsum board, partition wall panels, plaster, jointing plaster, and exquisite architectural decorative lines. It has excellent properties such as fire resistance, heat insulation, sound insulation, and automatic regulation of indoor humidity.
2. Cement Retarder: In the production of silicate cement, gypsum can control the setting speed of cement, preventing instantaneous solidification (flash setting) after the addition of water, thus ensuring sufficient working time for construction.
3. Mold Making and Crafts: Utilizing the micro-expansion and smooth surface characteristics of cooked gypsum during solidification, it is used to manufacture ceramic casting molds, mechanical casting molds, dental plaster models, and plaster sculpture crafts.
Food Grade
1. Soft Tofu Coagulant: Calcium sulfate is the core soy protein coagulant for making "soft tofu," "silken tofu," or "tofu pudding." Unlike magnesium chloride (bitumen), which rapidly coagulates, calcium sulfate has low solubility in water and releases calcium ions slowly and gently. This results in more uniform coagulation of soy milk, producing tofu with an extremely delicate texture, high water retention, a white and tender appearance, and no bitterness.
2. Baking and Pasta Improver: In baked goods such as bread and biscuits, it serves as a yeast nutrient (providing sulfur and calcium) and a dough conditioner. It promotes yeast fermentation and enhances dough elasticity.
3. Brewing Industry and pH Adjustment: In beer brewing, it is used to adjust the hardness and pH of brewing water (wort), promoting protein precipitation in wort and resulting in a cleaner beer taste.
Agricultural Grade
1. Saline-Alkali and Clay Soil Improver: Calcium sulfate is a powerful tool for improving severely saline-alkali and sodium-rich soils. The calcium ions in it can displace harmful sodium ions adsorbed on soil colloids, which are then leached away through irrigation, thus reducing soil alkalinity. It can also break down the dense structure of clay, improving soil permeability and drainage.
2. High-efficiency sulfur and calcium dual-supplement fertilizer: Targeting sulfur- and calcium-loving cash crops (such as peanuts, soybeans, potatoes, and alfalfa), it directly provides the two core medium-quantity elements, sulfur and calcium. In particular, applying gypsum to peanuts can significantly reduce the "empty shell rate" and greatly increase the pod filling rate.
Technical indicators:
Quality Indicators | Specification | Dihydrate | Anhydride |
GB1886.6-2016 | FCC V | GB 1886.6-2016 | FCC V |
Calcium sulfate (CaSO₄ ) w/% on a dry basis | Content | 98.0 | 98.0 | 98.0 | 98.0 |
Lead (Pb) / (mg/kg) ≤ | Lead | 2.0 | 2.0 | 2.0 | 2.0 |
Arsenic (As), / (mg/kg≤ | Arsenic | 2.0 | --- | 2.0 | --- |
Fluoride (F), w/%≤ | Fluoride | 0.005 | 0.003 | 0.005 | 0.003 |
Selenium (Se), w/%≤ | Selenium | 0.003 | 0.003 | 0.003 | 0.003 |
Drying loss, w/% | Loss On Drying | 19.0~23.0 | 19.0~23.0 | ≤1.5 | ≤1.5 |
Packaging:
Inner lining: polyethylene plastic bag; outer lining: woven plastic bag; each bag weighs 25 kg.