So far, the effect of purified diatomite better approach There are eight.
(1) acid leaching method which is currently prepared vanadium catalyst support and chemical product applications are more of a way. It is sour: diatomite = 1: 1, the amount of added sulfuric acid or hydrochloric acid and boiled for a certain time, so that the diatomite Al2 03, Fe2 03, the impurities with acid Ca0, Mg0, etc., generate soluble salts, then by pressure filtration, washing and drying, to obtain high quality pure grade diatomaceous earth. As for the type of acid, concentration, amount, boiling time, temperature, frequency selection, visualization purposes, origin, grade diatomaceous earth, and the type of impurity content, determined by experiment. However, as a vanadium catalyst carrier diatomaceous earth, acid must prevent chlorine ions into. Other possible applications with hydrochloric acid. In this way purified diatomite, Si02 content can increase 20% ~ 42%, Al2 03, Fe2 03 content can be reduced several times, the selection is very good; but its drawback is the amount of acid and washed with a large amount of water, and certain environmental pollution, the cost is relatively high, is only applicable to the production of high value-added products, does not apply to large, low value-added products.
Advantages (2) scrubbing the method is less investment in equipment, technology is relatively simple, relatively good working conditions. It is the first diatomite soak 5 ~ 6 h, and then by adding water and a dispersing agent NaOH, the slurry concentration of up to 40%, and stirred scrub that detrital minerals and clay minerals and diatom separation were precipitated sand level coarse soil, selection of suspension grade clay and diatomaceous earth. Scrub each time about 40 ~ 50min, coarse grade sand soil settling time of 6 ~ 8min, diatomaceous earth settling time of 6 ~ 7h. By scrubbing, detrital minerals and clay minerals can be removed relatively rich in diatoms, Si02 content increased, Al2 0. , Fe2 03 content decreased, diatomaceous earth quality better. The number of scrub, the more the better choice, especially high montmorillonite content of diatomaceous earth, the best results. The disadvantage is that the larger area, more water and a longer production cycle, high-precision soil drying energy consumption.
(3) This is the roasting method diatomite purification more economical, effective method, especially High loss of diatomite, the best results. It is the most effective removal of organic matter, the easiest method. It may be used alone, it can also be used in conjunction with other methods. Calcining temperature is generally 600 ~ 8000C.
(4) Director of sulfuric acid roasting method which Jan roasting method, the conversion method to avoid acid diffuse slow response of the short, evenly mixed with sulfuric acid diatomite, the 3800C low temperature roasting 1.Sh, then dip into the water wash, remove iron, aluminum water-soluble material, and the rest is the quality diatomaceous earth, after drying will have to fine soil. The disadvantage of this method is to produce acidic waste water immersion, further processing is required.
(5) from the spin - selective flocculation method which is a device low investment, simple process, low cost, the effect is more ideal method for purifying a diatomaceous earth. It is a spin-off by removing coarse detrital minerals, and then by adding selective flocculant so sticky ± particulate mineral flocculated thick clumps, so that the diatom remains separated from the clay minerals, achieve the purpose of purification.
(6) dry gravity chromatographic separation using this difference in detrital minerals diatomaceous earth, clay minerals and remains of diatoms density by ultrasonic vibration and cyclone separation, detrital minerals, clay minerals and remains of diatoms separated, to achieve the purpose of purification, the effect is quite good, can be significantly reduced Al2 03, Fe2 03 content. But more stringent requirements for the raw material, the moisture content is less than 5%, the grain size is less than 80 mesh, Si02 content of not less than 20%, bring some difficulties to the application.
(7) Thermal floating dressing method which is a method for the purification of diatomaceous earth is used as a vanadium catalyst carrier designed, simple process, with good results. It is based on diatomaceous earth clay minerals and organic carbon particles and diatom remains characteristic design and development, due to the different structure, water, heat-absorbing properties are also different. Above 65 ℃, according to the remains of diatoms diatom shells are very active, easy and clay and carbon particles separation characteristics of the diatomaceous earth by aging, broken, pulp, through the steam, after 40 ~ 45 min of ups and downs, the slurry will be divided into four layers, from top to bottom; the second layer is the highest amount of diatoms containing fine soil, after which the lean stream, with fine soil shrink frame filter, and dried, it will have fine soil.
(8) In addition to the integrated purification method 7 ways, but also tried to scrub - Settlement - strong magnetic separation - acid leaching - roasting and chopped pulp - Settlement - acid leaching - firing two methods, the effect is also good, but the process is slightly complicated . One important use of diatomaceous earth is as functional filler, but often after purification
Linjiang Huatong diatomite Mobile: 13943983955 Tel: 0439-5261777 owned diatomite clay reserves of over 10 million tons, the exploitation of the design capacity of 100,000 tons. Products are diatomaceous earth filter aid, diatomaceous earth adsorbent, diatomite functional filler, casting mold release agents, matting agents diatomite, diatom mud materials, pesticide carrier.