Bentonite is widely used:
1 casting industry
Casting bentonite is the largest user of bentonite, the annual amount of 1100000 tons.
Bentonite used in casting is mainly applied to the clay bonded sand, because bentonite has strong adhesion, high plasticity, good air permeability characteristics of stripping, stable physical and chemical properties, such as high temperature and wet conditions. Clay bonded sand for molding material production casting process, this is a long history, thriving in a variety of chemical bonded sand today, clay wet sand is still the most important molding material, its applicable scope, consumption of large, is any other material can not be compared to. High pressure molding, injection molding, molding, static modeling and non shock pressure vacuum process modeling in modern times, also is to use the clay wet sand as the premise, the ability to adapt to the other conditions of the clay wet sand strong. Casting bentonite mainly sodium bentonite and calcium sodium bentonite two, sodium bentonite is made from natural sodium bentonite or artificial Na bentonite processing, with its good reusability and the wet compression strength is high and the foundry industry are welcome. Because of good plasticity, can prevent the scab, scab, dropping block, sand mold collapse, and the molding cavity strong, high strength, convenient metal industry casting wet or dry mold, sand binder precision casting is preferred. Calcium sodium bentonite from natural calcium base bentonite processing, is widely used in light of casting sand binder. The utility and sand casting convenient and popular with users. Compared with other binder, bentonite has an important characteristic, is that it has certain heat capacity. As long as the heating temperature is not too high, the removal of free water bentonite as long as water, still can restore the adhesive ability. Binding capacity of bentonite in water can be manifested only after. Bentonite lose the binding ability, also with its dehydration. So far, that of bentonite in the water has three forms: a water free water, granular bentonite adsorbed water, heated to 100 ℃, can remove free water, removing free water bentonite, adhesive ability was not affected by the two kinds of water is strong; combined with water, long time heating at 110 ℃, bentonite can be removed completely free water, but does not remove firmly bound water. Has been completely removing free water bentonite, then at a higher temperature (200 ℃, 300 ℃) heating will continue to lose weight, there is still water loss. Bentonite by heating after dehydration, just add water, can completely recover bonding ability; three kinds of water is crystal water, also known as the structure of water. The lattice water to some or all removed only in high temperature. Lattice water removing swelling water, that the loss of binding capacity, become dead clay. Different bentonite, loss of binding capacity of different temperature. By differential thermal analysis experiments show that: Generally speaking, the failure temperature natural sodium bentonite is 638 ℃, calcium bentonite is 316 ℃. Artificial activation of Na bentonite, due to the activation of different conditions, the temperature is not a failure, but lower than the natural sodium bentonite.
2 drilling mud
Bentonite for drilling mud is bentonite second users, the annual amount of 700000 tons.
Bentonite is a kind of clay mineral with montmorillonite as main component, has strong water absorbability, can absorb the equivalent of 8 times the volume of the water itself, the volume expansion of 10 ~ 30 times, was suspended and colloidal state in aqueous solution. In oil, gas drilling work, want to use mud to cool the drill bit, remove debris, protect wall and equilibrium pressure. Bentonite dispersivity, grout amount is large, so it is ideal material for manufacturing drilling mud. As drilling mud bentonite, the most important requirement is the suspension properties, wet sieve analysis and moisture content.
The important effect of bentonite in drilling, makes its use very large. It is understood, the average recovery wells, about the use of bentonite 8 tons.
3 iron ore pellet
Iron ore pellet bentonite is bentonite third users, the annual amount of 450000 tons.
Iron ore pellet bentonite is one of the important material attached to the modern metallurgy industry, will concentrate powder adding bentonite bentonite and water after mixing pelletizer roll into a ball, and then drying and preheating, roasting has formed a high strength of pellet for smelting.
4 activated clay and clay particles
Activated clay is a kind of chemical products with bentonite processing, has multiple functions of activated carbon, and the price is cheaper than activated carbon. Therefore, a variety of mineral oil, the oil industry is widely applied in the petroleum industry of animal and vegetable oils, solid, liquid paraffin wax, fatty acid, regeneration of waste oil, ethanol and benzene decoloration refining. Can also be used as a Wine and juice clarification, sugar industry syrup purification, chemical industry, the catalyst powder pesticide additives etc..
Activated clay China manufacturer about 40, annual output of about 420000 tons. Device for producing ability is 50000 t/a. Activated clay production mainly concentrated in the northeast, North China, East China, production accounted for over 70% of the country. At present, the demand for activated clay in China is about 650000 t/a, annual imports of about 40000 tons.
Particulate clay is the activated clay as the main raw material, scientific formula, chemical processing and become, the appearance of unshaped granular activated clay, it has higher specific surface area and particle strength, stable performance, good selectivity, has a very high adsorption capacity, widely used in petrochemical industry aromatics purification, air kerosene refined, but also for refined oil, base oil, diesel oil, residual olefins, glial, Li Qing, and other impurities removing basic nitrogen compounds. At present, the clay particles is mainly to replace the America TONSIL particulate clay, used for the fitting of olefins removal, aviation kerosene, solvent oil refining, benzene refining, play a nitride removal, colloid, coloring effect. Particulate clay is sometimes called the oil filter oil filter using silica gel, silica gel can be good to remove the acid and the extract oil sludge, biological colloid, insulating material, can remove moisture, impurities and chromatographic analysis of hydrocarbon gases, and can be used for sewage treatment and toxic gas filtering and petrochemical industrial oil catalytic cracking.
The bentonite drier with adsorption activity, static reduction effect wet and odor removal etc.. Widely used in not using oil seal, gas seal products such as: optical instruments, electronic products, medical care, food packaging and military products and civil products of dry air seal. Compared with silica gel has the advantages of low cost, fast adsorption speed, preparation and low cost. And the other type of desiccant commercially available in comparison, not only the characteristics of adsorption speed, high adsorption capacity and non-toxic, tasteless, non corrosive, non environmental pollution, especially used in food packaging, no harm to human body.
The bentonite drier larger export volume.
6 litter (granular bentonite)
Litter (granular bentonite) uses the high quality natural bentonite, after high temperature drying refined, has a white color appearance, strong adsorption characteristics, the proportion of small, durable, suitable for family pets sanitation purposes.
Litter (granular bentonite) exports large.
7 sewage treatment
Bentonite used as animal feed processing wastewater, gasket odor bentonite can make animal feces easily dispersed, cleaning. The captive animal farms and slaughterhouses, aquatic products processing field generated sewage, odor and harmful to the environment, and bentonite in these places, the recovery efficiency of fertilizer.
Bentonite can be used as clarifier in muddy water, polluted water proofing agent, sewage treatment agent. Printing and dyeing wastewater with bentonite, coal gas washing wastewater, monosodium glutamate factory waste water, waste, removal rate of 99.5%.
And bentonite in the upstream of the reservoir the reservoir unclean substances into the bottom of the flocculation biological purification treatment.
8，The Construction Engineering
The lubrication of bentonite, bonding and sealing, thickening and gelling into mud, used for lining wall impermeable soil operations, such as wall construction, grouting, pile, caisson, land impervious, cement and concrete construction additives, solid water transport, sewage treatment and tunnel shield lubrication.
Bentonite impervious layer Pu River, the limited water leads to distant. Bentonite waterproof layer can be made of natural sodium bentonite powder is spread directly, also can use bentonite with local soil compaction, can also be bentonite sandwiched between two layers of fabric to form a waterproof (permeability) blanket (plate), fast to build a reservoir, reservoir water kiln, the canal.
Bentonite can be used as waterproof materials, waterproof felt waterproof board, corrugated cardboard loaded bentonite sandwiched between two layers of non-woven fabrics of bentonite and a layer of non-woven fabric with a plastic board is clamped in the middle of the bentonite double waterproof board, this material has been widely used in the subway, the bottom of the dam, the landfill of underground engineering in the process of. Bentonite has high water tightness and self repair function of the restoration, waterproof have compactness (sodium bentonite in water to form the diaphragm, the compactness of the 30cm thickness of clay layer thickness is about 5mm, equivalent to 100 times of water), self performance (sodium bentonite and water reaction when, with expansion force, L3l6 times so it can repair 2mm within the cracks of concrete surface with waterproof performance) and permanent (sodium bentonite does not occur with aging or corrosion) etc.. Harmless to human body of bentonite, environmental performance is excellent. Simple construction. No need for heating and paste, not affected by temperature. At the same time, short construction period, compared with other waterproof materials, construction is relatively simple compared to soft. Only the nails and washer. After the construction does not need the special inspection, if found waterproof defects also easy to repair.
As food additives and emulsifier in food, can be used as calcium and diet food.
Bentonite can make juice, juice clarification.
Bentonite can soften hard water.
Bentonite to fix nitrogen deposition method for wine clarification, reduce acetaldehyde formation and the formation of hydrogen sulfide, eliminate all alien smell.
Bentonite in papermaking industry as multifunctional white paint, anti pitching adsorption agent, maintaining agent, in the pulp of rheological modifier role in machinery it still pulper.
Bentonite can also produce coating. As the viscosity regulator and white mineral filler in the coating, which can partially or completely replace titanium dioxide; also can replace part of polyvinyl alcohol, as well as binder for nonwoven, gypsum particles.
Bentonite of oxidized starch adhesive was modified, which can not only improve the solid content, gum reduced the water, also can plug and fill the paper fiber (especially the straw pulp paper) space, reduce the moisture permeability, thus improves the initial adhesion adhesive and drying speed. Experiments prove that the bentonite effect is good, and the price is low, is the ideal drying agent.