Application of 1. gray calcium in putty coatings
The main components of calcium ash are calcium oxide chemical formula CaO, calcium hydroxide chemical formula Ca(OH)2 (calcium oxide (lime), magnesium, phosphorus, gypsum, alum. Thousands of years ago, the ancients used it as an inorganic adhesive. China's Great Wall, Zhaozhou Bridge used in the construction of the mortar (all lime powder to add glutinous rice juice as a bonding agent). It has not been rotten for thousands of years. It will become harder and harder in water, and it has strong oxidation resistance.
Gray calcium has a certain adhesion and strength, is a strong alkaline. The PH value is about 15 (about 16.5 without electrolyte) and the raw material is white lime after high-calcium limestone is calcined at a high temperature of about 900 degrees. (I. e. calcium oxide) after burning loss of lime calcium oxide content of more than 90%. Then add a certain amount of electrolyte by modified grinding into 300 mesh is gray calcium.
The modified calcium ash calcium hydroxide content increased, the pH value decreased, water absorption decreased, not easy to thicken cracking, in the putty coating is very stable. Due to the geological structure, the south of the Yangtze River is represented by Zhejiang Jiande, Guangxi Guilin, Yunnan Dali, Jiangxi Xinyu, and gray calcium is the best. It has the advantages of high calcium content, high whiteness, low water absorption, good bonding strength, and low addition amount. The north of the Yangtze River is northern gray calcium, which is generally low in calcium content, large in volume, light in specific gravity, large in water absorption, low in adhesion, slightly low in strength, and relatively more glue.
Coatings, toughened imitation porcelain putty added to the cheap gray calcium is an energy-saving carbon reduction, absorption of indoor carbon dioxide, indoor air purification function of environmentally friendly coatings. Calcium oxide needs to continuously absorb carbon dioxide in indoor air and convert it into calcium carbonate, which requires a long process. These functions are gradually recognized by people.
Application of 2. Heavy Calcium Carbonate in Coatings
Heavy calcium carbonate referred to as heavy calcium chemical molecular formula CaCO3, double fly powder, large white powder, old powder. It is a kind of natural white calcite, translucent crystal, ground into fineness 325-1250 mesh, (calcium carbonate content above 98%, neutral (inert),PH value 7-8, low water absorption, high whiteness, good brightness, and certain refraction effect. It is an indispensable high-quality filler in paint putty. General putty with 325-400 mesh, latex paint with 800-1250 mesh. Another is also known as large white powder, the raw material is large white stone (marble), calcium carbonate content is low, no crystal below 95%, brightness and whiteness is low, water absorption is larger than calcite, no refractive index. But the price is low, is the production of putty general filling material.
Properties and Application of 3. Talcum Powder in Coatings
Talc is an aluminum clay with soft texture. Its main components are calcium carbonate chemical formula CaCO3, silicon oxide formula Si2O3, aluminum oxide formula Al2O3, magnesium, potassium, sodium and other trace elements. Talc has no crystals, no refractive index and is white. Its whiteness is above 92, PH value is 7-8, is inert, acid and alkali resistant, has large water absorption and excellent hand feeling smoothness. As a filler, the general latex paint with a whiteness of 92 or more, fineness 800-1250 mesh. For interior and exterior wall putty, the performance of the proportion of calcium is better, the general use of fineness 325-400 mesh whiteness above 80. However, it is not suitable for use in paste tempered imitation porcelain coatings. Because it's harder than calcium. High-quality talcum powder can also be used in large quantities in medicine.
Use of 4. kaolin in coatings and rubber plastics
Kaolin is aluminum clay class, the main raw material for the coal seam in the biological, also known as coke gem. The main component is aluminum oxide chemical molecular formula AL2O3, silicon oxide, calcium, potassium, sodium, magnesium and other trace elements, the ore is grayish brown, light white.
After high temperature calcination at about 850 degrees, it is ground into different fineness, high quality kaolin, high aluminum oxide content, high whiteness, general whiteness 92-96 is excellent, kaolin is divided into calcined kaolin, which is called sodium-based activated kaolin after surface treatment.
Excellent grade activated kaolin is used in coatings, interior and exterior latex paints, and the fineness needs 800-1250 mesh. It thickens in the later stage of coating. The aluminum oxide contained in it will migrate to the surface of the coating layer, resulting in a certain hardness and texture.
As a rubber, tire, plastic, wire and cable available in 325-600 mesh, than the use of light calcium, calcium tensile strength is much higher.
Application of 5. Bentonite in Coatings
Bentonite is a kind of clay, divided into calcium base and sodium base. After surface treatment, it is sodium base after activation, and it is also the most commonly used additive in paint putty. Chemical formula: Al2O3 · 4SiO2 · H2O. And silicon oxide, calcium aluminum, magnesium, potassium, sodium and other trace elements, viscosity is very strong, mainly used in latex paint, paint, interior and exterior wall putty. Main properties: viscosity, thickening, water retention, anti-precipitation, anti-sagging, providing coating pseudoplasticity. Due to the high viscosity, it is not allowed to be directly added to water to avoid clumping. It can be added in the form of thick paste (do not stir after adding water) or mixed with dry powder filler. Because of its low whiteness, it is easy to thicken and harden in the later period. The addition of paste imitation porcelain and tempered latex paint shall not exceed 2% (except dry powder paint), otherwise the paste has a short storage period and is easy to thicken and harden.
The main use and performance of 6. cooked gypsum powder in building materials
Cooked gypsum powder, also known as hemihydrate gypsum, has a chemical formula of 2CaSO4 · H2O, which is acidic, with a PH value of 5-6.5, soluble in water, (raw gypsum is insoluble in water). The main raw material is natural gypsum translucent crystal, which is ground into 300 mesh powder after calcination at a high temperature of 850 degrees, with an excellent whiteness of 80-88.
Desulfurization gypsum and phosphoric acid gypsum powder are all recycled gypsum with low whiteness. Semi-hydrated gypsum is mainly used for building leveling mortar (filling pits well), leveling putty, plastering gypsum, gypsum powder (quick dry powder) and gypsum board and gypsum line for decoration. Portland cement, concrete, steam block brick additives, fast solidification and strong plasticity. (setting time 5-10 minutes), in case of uneven wall, mixed with part of the semi water gypsum and gypsum retarder, do leveling putty, will receive excellent results.
Application Range of 7. Light Calcium Carbonate in Coating Plastic Rubber
Light calcium carbonate is referred to as light calcium chemical molecular formula CaCO3, which is called active calcium after surface treatment. Generally, the content of calcium carbonate is ≥ 98%, which is neutral, PH value is 7-10, whiteness is high, and above 92 is excellent. It has light specific gravity and great water absorption, nearly double that of ash and twice that of heavy calcium. Suspension is excellent, in the coating with a large amount of glue, the construction of the feel is better, the general cold soluble glue and cellulose should not be used (for emulsion, polyvinyl alcohol glue). But its hardness is poor, not water resistant, because of the suspension of good suitable for polyvinyl alcohol hot glue do imitation porcelain use, it is generally used in latex paint, rubber, tire plastic, wire and cable filling material.