Calcite is a common calcium carbonate mineral with the chemical formula of CaCO3, which is widely used in various fields. Its crystal forms are diverse, which can be flake, plate, cone, column, etc., and the colors are different, including colorless, white, pink, green, yellow, red, blue, gray and black. The variability and rich colors of calcite make it one of the important ornamental minerals. Calcite belongs to the trigonal system and has a calcite family structure of the island carbonate mineral subclass. It has various forms. According to statistics, there are more than 600 different polymorphs. The physical properties of calcite include Mohs hardness 3 and density of about 2.71g/cm³. It has complete cleavage in three directions and can form rhombus-shaped fragments. The chemical properties of calcite are soluble in hydrochloric acid, so it needs to be carefully protected during transportation and cleaning. The application range of calcite is very wide, covering many fields such as construction, chemical industry, metallurgy, and medicine. Building materials In the field of construction, calcite is one of the most important rock-forming ores and is widely used in the production of cement, lime and other building products. Its addition can improve the process properties of materials and increase strength and durability. For example, calcite is an indispensable raw material in the manufacture of building materials such as limestone and marble. In addition, calcite is also used in the production of decorative materials such as architectural coatings and wall coatings to provide better whiteness and gloss. Chemical industry In the chemical industry, calcite, as one of the main sources of calcium carbonate minerals, is widely used as a chemical additive and filler. It can be used to manufacture chemical products such as plastics, rubber, paints, and coatings to improve the physical properties and process properties of the products. Especially in the papermaking industry, calcite, as a filler, can improve the gloss and smoothness of paper. Metallurgical industry In the metallurgical industry, calcite can be used as a flux in the ironmaking process to reduce the furnace temperature, accelerate the reduction reaction of iron ore, and increase the yield of pig iron. At the same time, it can also be used as a desulfurizer in steel smelting, converting sulfides in molten iron into volatile substances, reducing the sulfur content in steel and improving the quality of steel. In addition, calcite can also be used as a sand core material in the foundry industry to improve the surface quality and dimensional accuracy of castings. Medical field The application of calcite in the medical field is reflected in its use as a source of limestone, which can be used to make lime and then as a raw material in pharmaceuticals. Lime can be used to make calcium agents, such as calcium tablets, calcium powder, etc., for the prevention and treatment of calcium deficiency. Other uses The birefringence of calcite also makes it uniquely used in the optical field, such as for the manufacture of optical instrument components such as polarizing prisms. In addition, calcite is also used in food additives, environmental protection treatment and other fields. In order to achieve the above market applications, calcite sorting is essential. At present, the more common calcite sorting methods on the market are gravity separation, magnetic separation, flotation and photoelectric separation. Among them, the gravity separation method uses the difference in density between calcite and other minerals to achieve separation by gravity separation. This method is suitable for the sorting of ores with large density differences. Magnetic separation is to separate ores with magnetic differences through magnetic separation technology. This is often used to distinguish between magnetic minerals and non-magnetic minerals. Because both separation methods have certain limitations. Gravity separation equipment usually requires a large site, which increases the investment in infrastructure, and the accuracy of gravity separation is not high, and the separation effect is not ideal. Magnetic separators are mainly suitable for finer magnetic particles. For larger particles, the separation effect may be limited. At the same time, the separation effect for non-magnetic ores and impurities is not ideal. In addition, like gravity separation equipment, magnetic separation equipment also requires a large site and requires increased investment in infrastructure. Photoelectric separation is mainly used to sort calcite through ore color sorters. Ore color sorters use the differences in the optical properties of ores for sorting, and use high-resolution CCD image sensors and high-speed computing processing units to quickly identify and separate ore particles. This technology not only improves the efficiency and accuracy of sorting, but also reduces environmental pollution and energy consumption. CCD Sensor Based Ore Color Sorter As an emerging ore sorting technology, photoelectric sorting technology has shown many significant advantages in the application of calcite sorting. High efficiency Photoelectric separation technology can quickly remove a large amount of useless gangue, reduce the pressure of subsequent mineral processing links, and improve separation efficiency. This technology can process a large amount of materials in a short time, and has high separation accuracy, which helps to improve the grade of calcite. Low cost Compared with traditional physical and chemical mineral processing, the only energy consumption of photoelectric separation is electricity consumption, and the cost of mineral processing per ton is about 1 yuan, which is much lower than the average cost of traditional methods. Green and environmental protection Photoelectric separation has zero pollution to the environment and is a greener way of mineral processing. This is especially important today when environmental protection is increasingly valued. Technological progress With the development of computer technology and artificial intelligence technology, the intelligence level of photoelectric separation equipment has been continuously improved, which can better adapt to the separation needs of different types and complex ore structures. Strong adaptability By introducing cutting-edge technologies such as artificial intelligence and big data analysis, the intelligence level and adaptability of the photoelectric separation system have been greatly improved, and it can process more types of ores. High safety Photoelectric separation equipment does not need to add any chemical agents during operation, avoiding the safety risks that may be caused by chemical agents. Hefei Mingde Optoelectronics Technology Co., Ltd. has been professionally engaged in the research and production of intelligent sorting equipment for mining for more than ten years. Its ore color sorter and AI ore sorter have excellent performance in the sorting of calcite, especially the AI ​​artificial intelligence sorter, which can accurately extract and distinguish the surface features of calcite and miscellaneous stones, and achieve high-precision sorting. The machine can produce about 200 tons per hour, which can meet the production needs of large mines. MINGDE AI Sorting Machine Flotation technology, as an efficient mineral processing method, also plays an important role in the sorting of calcite. With the development of technology, the flotation methods of calcite have also become different, and we will introduce them separately. Traditional flotation separation Traditional calcite flotation separation mainly relies on the action of chemical agents, including the use of inhibitors and collectors. Inhibitors are used to reduce the floatability of calcite, while collectors are used to enhance the flotation ability of target minerals (such as fluorite). Although this method can achieve separation to a certain extent, its efficiency and selectivity still need to be improved. New flotation separation technology Recently, researchers have proposed a variety of new methods for the flotation separation of calcite and fluorite. For example, some studies have studied the effects of glucose and Al3+ on the flotation separation of calcite and fluorite by means of microflotation experiments, scanning electron microscopy (SEM), solution chemical calculations, X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT). In addition, there are studies that use the regulator PDP to strengthen the DDA system, and achieve effective separation of brucite and calcite by optimizing the operating parameters of the flotation machine and adjusting the type and concentration of the flotation agent. Currently, the sorting technology of calcite is developing rapidly in the direction of high efficiency, environmental protection and intelligence. Through the continuous optimization of chemical agents and novel intelligent sorting technology, the separation efficiency and purity of calcite have been significantly improved, which is of great significance for improving the utilization efficiency of mineral resources and promoting the sustainable development of the mining industry. In the future, with the continuous advancement of science and technology, the sorting technology of calcite is expected to achieve more innovations and breakthroughs. Overall, as a multifunctional mineral, calcite has a wide range of applications. With the continuous development of science and technology, the application areas of calcite will continue to expand, bringing more convenience and contribution to human production and life.

Calcium carbonate (CaCO3 for short) is an inorganic compound, commonly in the form of white solid powder or granules, and is one of the most abundant substances on earth. It is widely distributed in nature and is the main component of rocks, corals, pearls and the shells of many organisms. Calcium carbonate is chemically insoluble in water, but can release carbon dioxide gas in an acidic environment. Calcium carbonate can be divided into several types according to different production methods, particle size, morphology and uses. The focus of this discussion is to understand the difference between heavy calcium carbonate and light calcium carbonate, both of which are widely used in industrial applications. Heavy calcium carbonate Heavy calcium carbonate (GCC for short) is made by physical methods, usually mechanical crushing of natural minerals such as calcite, limestone, chalk, and shells. It is characterized by irregular particle shape, wide particle size distribution, and an average particle size of 5-10μm. Heavy calcium carbonate has a large bulk density, generally between 0.8-1.3g/cm³, and a low oil absorption value, generally 40-60mL/100g. Light calcium carbonate Light calcium carbonate (PCC for short) is produced by chemical precipitation. Its particles are regular in shape and can be regarded as monodisperse powders. The particle size distribution is narrow and the average particle size is generally 1-3μm. The bulk density of light calcium carbonate is small, generally between 0.5-0.7g/cm³, and the oil absorption value is high, generally 60-90mL/100g. Active calcium carbonate Active calcium carbonate is obtained by surface modification on the basis of ordinary calcium carbonate. It is hydrophobic and suitable for occasions with specific needs. Difference Production method: Heavy calcium carbonate is mainly produced by physical crushing, while light calcium carbonate is produced by chemical precipitation. Particle size and shape: The particle size and shape of heavy calcium carbonate are irregular, while the particle size and shape of light calcium carbonate are regular. Bulk density: The bulk density of heavy calcium carbonate is greater than that of light calcium carbonate. Oil absorption value: The oil absorption value of heavy calcium carbonate is lower, while the oil absorption value of light calcium carbonate is higher. Whiteness: The whiteness of light calcium carbonate is generally higher than that of heavy calcium carbonate. Surface modification: Activated calcium carbonate has been surface modified and is hydrophobic. Industrial application Calcium carbonate is widely used in industry. It can be summarized into the following major areas: 1. Rubber industry In the rubber industry, calcium carbonate is used as a filler and reinforcing agent in large quantities. It can effectively improve the hardness, wear resistance, tensile strength, tear resistance and aging resistance of rubber. In addition, calcium carbonate also helps to reduce production costs and increase the output of rubber products. 2. Plastic industry In the plastic industry, calcium carbonate also plays an important role. It can improve the hardness, wear resistance, heat resistance and weather resistance of plastics, while also reducing production costs and improving production efficiency. 3. Construction industry In the construction industry, calcium carbonate, as a raw material for cement, can significantly improve the compressive strength, flexural strength and durability of cement. It can also improve the construction performance of cement and improve the seismic performance of buildings. 4. Agricultural field In the agricultural field, calcium carbonate is used as a fertilizer and feed additive, which can improve the disease resistance of crops, promote root growth and soil acid-base balance, and also improve the yield and quality of crops. 5. Medical field In the medical field, calcium carbonate is used as a calcium supplement and antacid to treat diseases such as osteoporosis and rickets. It can also be used as a pharmaceutical excipient for the manufacture of tablets, capsules and injections. 6. Environmental protection field In the environmental protection field, calcium carbonate is used as an adsorbent and precipitant to remove harmful substances from water, reduce the hardness of water bodies, and improve water quality. It can also be used in waste gas treatment and soil remediation. 7. Cosmetic industry In the cosmetics industry, calcium carbonate is used as an additive for beauty products, which can improve skin texture, increase skin elasticity, and make the skin smoother and more delicate. 8. Other fields In addition to the above application fields, calcium carbonate is also widely used in ceramics, glass, pigments and other industries. It can improve the hardness, wear resistance, corrosion resistance and transparency of materials and other performance indicators. Processing Processing of light calcium carbonate Light calcium carbonate is produced by chemical reaction precipitation. Its production process mainly includes: Calcination stage: calcine the limestone raw material to generate calcium oxide and carbon dioxide. Digestion stage: put the calcined calcium oxide into a continuous digester and add water to digest it to obtain calcium hydroxide emulsion. Carbonization stage: react the calcium hydroxide emulsion with carbon dioxide to generate calcium carbonate precipitation. Dehydration and drying stage: dehydrate and dry the calcium carbonate precipitation to obtain dry calcium carbonate powder. Crushing and screening stage: crush and grade the dried calcium carbonate through crushing and screening equipment to obtain the product of the required fineness. Packaging stage: package the graded calcium carbonate powder to obtain the final product. Processing of heavy calcium carbonate The production process of heavy calcium carbonate generally includes the following steps: Crushing: use a crusher to coarsely crush raw materials such as calcite for subsequent fine grinding. Sorting: generally use hand selection, magnetic separation equipment or photoelectric separation equipment to remove impurities from the ore. CCD Sensor Based Ore Color Separator The color sorter and artificial intelligence sorting launched by Mingde Optoelectronics Technology Co., Ltd. have excellent performance in the sorting of heavy calcium carbonate. They can accurately compare the sorted materials according to the surface characteristics of the ore to achieve accurate sorting. AI Sorting Machine The heavy-duty sorting machine launched by the company can sort large-particle ore, which not only avoids over-crushing of the ore, but also increases the output of ore sorting. Heavy Duty AI Sorting Machine Fine grinding: Fine grinding is carried out by Raymond mill, pendulum mill, roller mill and other equipment to obtain fine limestone powder. Classification: The powder is graded by the classifier, and the powder that meets the particle size requirements is packaged and stored as a product, and the powder that does not meet the requirements is returned to the mill for re-grinding. Packaging and storage: The powder that meets the particle size requirements is packaged and stored to complete the entire production process. As a multifunctional and widely used material, calcium carbonate not only plays an important role in the traditional industrial field, but also shows new possibilities in emerging fields. With the development of science and technology, the application prospects of calcium carbonate will be broader.