Can Gypsum Be Eaten?
I. Can Gypsum Be Eaten?
Answer: Yes
II. Basic Introduction
Gypsum is a monoclinic crystal system mineral, primarily composed of calcium sulfate (CaSO₄) hydrate.Gypsum is a versatile industrial and construction material. It is used as a cement retarder, in gypsum building products, model making, medical food additives, sulfuric acid production, paper fillers, paint fillers, and more.
The microporous structure and dehydration properties of gypsum and its products confer excellent sound insulation, thermal insulation, and fire-resistant characteristics.
III. Structural Form
Monoclinic crystal system, with a0=0.568nm, b0=1.518nm, c0=0.629nm, β=118.23', Z=4.The crystal structure consists of [SO₄]²⁻ tetrahedra bonded to Ca²⁺ to form a double layer along the (010) plane, with interlayer bonding via H₂O molecules. Perfect cleavage occurs along this direction. Ca²⁺ has a coordination number of 8, bonding to 6 O²⁻ atoms from adjacent [SO₄] tetrahedra and 2 H₂O molecules.H₂O molecules bond to O²⁻ in [SO₄] via hydrogen bonds, while water molecules connect through molecular bonds. Orthorhombic class, C2h-2/m (L2PC). Crystals commonly develop as plates, though granular forms also occur. Simple forms are frequent: parallel twins b, p; orthorhombic columns m, l, etc. Crystal faces often exhibit longitudinal striations; occasionally lentil-shaped.Twinning is common: one type is the Gallic twinning (or swallowtail twinning) with (100) as the twin plane; another is the Paris twinning (or arrowhead twinning) with (101) as the twin plane. Aggregates are mostly dense granular or fibrous. Fine-grained massive forms are called snowflake gypsum; fibrous aggregates are called fibrous gypsum.Rare rose-like aggregates formed by lenticular crystals occur. Earthy and lamellar aggregates are also present. IV. Major Deposits The world's largest gypsum producer is the United States. Gypsum deposits are distributed across 22 U.S. states with 69 mines, the largest being Dodge City, Iowa. Canada ranks second. France leads European gypsum production, followed by Germany, the United Kingdom, and Spain. China possesses abundant gypsum resources, with deposits found in 23 provinces (regions). There are 169 proven-reserve mining areas, totaling 57 million tons of ore reserves.followed by Germany, the United Kingdom, and Spain. China possesses abundant gypsum resources. Gypsum deposits occur in 23 provinces (autonomous regions) nationwide. There are 169 mining areas with proven reserves, totaling 57.6 billion tons of ore reserves. Regionally, Shandong Province holds the largest gypsum reserves, accounting for 65% of the national total, followed by Inner Mongolia, Qinghai, and Hunan.Major gypsum mining areas include Dige Town in Zaozhuang, Shandong; Etuqi Banner in Inner Mongolia; Yingcheng City in Hubei; Hunchun in Jilin; Nanjing in Jiangsu; Dawenkou in Shandong; Qinzhou in Guangxi; Taiyuan in Shanxi; and Zhongwei in Ningxia.China possesses abundant gypsum mineral resources, with total proven reserves of all gypsum types estimated at approximately 57 billion tons—ranking first globally. These reserves are distributed across 23 provinces, municipalities, and autonomous regions. Ten regions hold reserves exceeding 1 billion tons: Shandong, Inner Mongolia, Qinghai, Hunan, Hubei, Ningxia, Tibet, Anhui, Jiangsu, and Sichuan. The Northeast and East China regions exhibit relatively scarce gypsum resources.
China's gypsum resources consist primarily of common gypsum and anhydrite, with anhydrite accounting for over 60% of the total. Premium-grade gypsum (Grade A and Grade B) constitutes only 8% of the total reserves, while fibrous gypsum makes up a mere 1.8%. Consequently, while China is a major gypsum reserve holder, it is simultaneously a country with limited reserves of high-quality gypsum.Premium gypsum resources are primarily distributed in areas such as Yingcheng and Jingmen in Hubei, Hengshan in Hunan, Sanshui in Guangdong, Zaozhuang in Shandong, and Pinglu in Shanxi. Some mining sites have been overexploited and are nearing depletion, while others suffer from wasteful utilization due to the difficulty of separating premium gypsum from low-grade deposits. Consequently, the proportion of premium gypsum resources that China can actually mine and effectively utilize is even smaller.
Although China's gypsum industry started late with weak foundations, it developed rapidly. By 1995, gypsum production surged to 26.59 million tons, surpassing the United States to become the world's largest gypsum consumer. By 2004, annual domestic raw gypsum production exceeded 30 million tons, with total consumption reaching approximately 35 million tons.China currently operates over 500 gypsum mines, with approximately 50 large and medium-sized mines producing over 100,000 tons annually, accounting for 40% of total output. Small-scale township mines contribute about 60% of total production. By extraction method, open-pit mining accounts for roughly 30%, while underground mining constitutes approximately 70%.In underground gypsum mines, the average recovery rate remains below 30% due to various factors. Premium resources designated for priority extraction are not being developed rationally or utilized effectively, resulting in severe and heartbreaking resource waste!
The most widely used form of natural gypsum is dihydrate gypsum, whose active component is calcium sulfate dihydrate. Gypsum is typically graded based on the content of calcium sulfate dihydrate in the ore.Gypsum has broad application fields and diverse product types, with different uses demanding varying raw material qualities. High-grade gypsum is primarily used as raw material for specialty gypsum products such as food-grade, medical-grade, art supplies, modeling materials, and chemical fillers. Gypsum ore with calcium sulfate dihydrate content below 60% is rarely utilized.Gypsum ore exceeding 60% CaSO₄ is utilized across various sectors like building materials and construction, depending on its specific composition. Global consumption patterns vary by country. Developed nations exhibit a higher proportion of processed gypsum products, with consumption structured as follows: 45% for finished goods, 45% for cement production, and 10% for other applications.Developing countries predominantly focus on primary ore applications, heavily reliant on the cement industry, with the proportion of gypsum products gradually increasing alongside economic development. China's consumption structure is roughly as follows: 84% used as a retarder in cement production, 6.5% for ceramic molds, 4.0% for gypsum products and wall materials, and 5.5% for chemical and other industries.As China's cement output continues to expand, demand for gypsum will correspondingly increase. Concurrently, with China's rapid economic growth, the gypsum industry—particularly gypsum products—holds immense development potential. Various gypsum products and gypsum wall materials will experience accelerated growth, inevitably driving a sharp rise in gypsum demand. As traditional ceramics and other specialty industries develop, high-quality gypsum resources are diminishing, making the development and utilization of gypsum resources increasingly critical.Therefore, to ensure the sustainable development of the entire gypsum industry and enable the broader application of green, eco-friendly, and healthy gypsum building materials and products in people's lives, the optimized utilization of limited gypsum resources is imperative.