Diatomite is a micro one-celled phytoplankton. There are many kinds of diatomite to live in fresh water lakes and sea. They often stay close to water surface, so they are part of rich phytoplankton. Before their death, they are the bottom of the food chain. After their death, they leave beautiful skeletons with symmetric structure just like micro pearls. Most of other plants use solar energy to synthesize cell wall tissue, while diatomite uses amorphous SiO2 in water to build delicate high strength micropore shells.
Diatomite use and index The final product produced from diatomite is called diatomite powder, qualified concentrates of diatomite, baked diatomite, and fluxing agent baked diatomite with different technical indices. About five hundred types of products are widely used. It is very important to use diatomite as drainage agent. The diatomite powder product can filter solid particles, suspending solid, colloidal particles and bacteria out from filtrate in order to filter and purify liquid. For physical and chemical properties of diatomite drainage agent, see Table 4.21.1. In this table, GZ is the drainage agent made from diatomite dressing, drying below 800°C and grading; PZ is the drainage agent from diatomite dressing, baking at 800~1 200°C and grading; and ZZ is the drainage agent from diatomite dressing, baking at 800~1 200°C in the presence of ;fluxing agent and grading.
Physical and chemical properties of diatomite drainage agent Drainage agent is mainly used in for filtration in beer brewery, pharmaceutical industry (to filter the bacteriophage, blood plasma, vitamin, synthesize pharmaceutical, injection solution, etc.), water filtration, grease industry, organic solution, coatings and dyestuff, fertilizer, acid, base, sapid substance, sugar, liquor, etc. The second most important use is that diatomite works as functional fillings in coatings, plastics, rubber, pharmaceutical, toothpaste, abrasive material and chemical agents, etc. for example, it is used as structural fillings to adjust coating gloss and brightness. In addition, diatomite is used as abrasive material in silver polishing powder to polish metal surface. It is also used as adsorbent to adsorb the water, which is equivalent to 2.5 times its own weight. Even if the specially processed diatomite powder mixes with the water, which is equivalent to 50% of its own weight, the powder still seems to dry. Technology classification:Diatomite can be classified into three categories according to production process: Dried product: produced from diatomite drying at 100°C-300°C, breaking by high pressure air stream, impurity removal, and grading; offwhite to light yellow. Baked product: produced from diatomite sorting, baking at 700°C-900°C, breaking by high pressure air stream, and grading; orange to sorrel. Fluxing agent baked product: produced from diatomite sorting, baking at 900°C-1200°C in the presence of fluxing agent, breaking and grading; pink white to white. Technical indexPhysicochemical index Project Grade SiO2 %≥Al2O3 %≤ Fe2O3 %≤ CaO %≤ MgO %≤ Filter aid 87-95 4 1.5 0.6 0.5 Filler 80-90 5 1.5 0.6 0.5 Use classificationDiatomite use: (1) Diatomite is widely used as drainage agent in solid-liquid separation in the such industries as food, beverage, pharmaceutical, petroleum, chemical, dyestuff and water treatment, etc.; (2) Diatomite is widely used as thermal insulation material in thermal insulation mortar for inner and outer walls, calcium silicate board, industrial kiln, etc., in the building material industry; (3) Diatomite is widely used as antiagglomerant in food deoxidation fresh-keeping agent; as soil improvement agent in grass of playground and green meadow; as Environmental dessicant in food, pharmaceutical, electric appliances, instrument, garment, etc.; and as oil absorbent (ground absorbent) in environmental protection projects; (4) Diatomite is widely used as functional fillings in rubber, plastics, coatings , anti-mosquito incense, paper, abrasive material, polishing paste, toothpaste, cosmetics, asphalt, cement, ceramic product, etc.; (5) Diatomite is widely used as carrier in vanadic sulfate catalyst, phosphoric acid catalyst, pesticide and fertilizer; (6) Diatomite is widely used as coagulant aid in wastewater treatment. Diatomite is also called industrial monosodium glutamate. It is one of indispensable raw material in modern industry because it can meet the need in many industries