35results about How to "Coarse particles" patented technology

The invention discloses a process for improving the quality of phosphorus chemical industry waste smoke desulfurization gypsum, and the process comprises the following steps: mixing a desulphurized absorbent with slag washing water; stirring to form an even slag slurry; carrying out rotational flow separation on the slag slurry; removing bottom flow slag to obtain an overflowing liquid; configuring additive mixed liquor; mixing and stirring the additive mixed liquor and the overflowing liquid to obtain even size; contacting the size with the phosphorus chemical industry smoke; adsorbing sulfur dioxide and phosphorus compound in the phosphorus chemical industry smoke; carrying out airoxidation to form a gypsum liquid; carrying out the rotational flow separation on the gypsum to obtain top flow liquid and bottom flow desulfurization gypsum liquid; reusing the top flow liquid; and dewatering the bottom flow desulfurization gypsum liquid to obtain the desulfurization gypsum. According to the process disclosed by the invention, the problems of small desulfurization gypsum crystalline particle and difficulty in separation in the phosphorus chemical industry waste smoke desulfurization system are solved, gypsum crystal with big particle and low moisture content is obtained, and the filtering performance of the gypsum is improved.

The invention relates to a neutralization aluminum removing method for a sodium chromate alkali solution. The carbon dioxide is used as a neutralizer for the neutralization aluminum removal of the sodium chromate alkali solution, and a two-section neutralization method is adopted; in the first section, a neutralization pH value is controlled so that most of aluminum in the alkali solution forms and separate aluminium hydroxide sediment with thick and big particles; in the second section, the residual aluminum in the solution is completely neutralized and precipitated by continuously using thecarbon dioxide, and the aluminum sediment precipitated in the second section is returned to the first section; the solution after the neutralization aluminum removal by the carbon dioxide is neutralized and acidized by a by-product chromium-contained sodium hydrogen sulfate in the production process of chromium salt, the chromium-contained sodium hydrogen sulfate is comprehensively utilized, and the trivalent chromium is recycled. The invention has the advantages of easy separation and washing of aluminum mud, low water content, low chromium band loss, easy comprehensive utilization, and the like.

The invention provides a method for treating wastewater containing heavy metal ions through phase transformation of MgCO3.3H2O, and belongs to the technical field of wastewater treatment. The method comprises the following steps: taking wastewater solution containing heavy metal ions, regulating the temperature to 50-60 DEG C, regulating the pH value to 4-8, adding MgCO3.3H2O into the wastewater solution containing the heavy metal ions, and oscillating the solution at constant temperature, so as to obtain wastewater turbid liquid containing the heavy metal ions; heating the wastewater turbid liquid to 55-90 DEG C, stirring at constant temperature for 30-90min, standing, aging, and filtering obtained mixed solution containing precipitation, so as to obtain clear liquid and a filter cake, wherein the mass ratio of MgCO3.3H2O to the heavy metal ions is (4-50):(0.01-1); the heavy metal ion(s) is / are one or more heavy metal ions of Cr<3+>, Pb<2+>, Ni<2+>, Cu<2+>, Zn<2+> and Cd<2+>. According to the method, the wastewater containing the heavy metal ions is treated, the treatment cost is lowered, and the secondary resource recycling of heavy metals can be realized.

The invention discloses a method of preparing sodium dichromate, comprising the steps of (1), subjecting chromite and alkali solution to liquid oxidation, subjecting slurry to solid-liquid separation after reacting to obtain liquid phase A and solid phase B; (2), washing the solid phase B with circulatory alkali liquid, subjecting post-washing slurry to solid-liquid separation to obtain liquid phase C and solid phase D; (3), crystal-dissolving the solid phase D with sodium chromate crystal with water and iron residue washing liquid, carrying out solid-liquid separation to obtain crystal-dissolved liquid and iron residue, washing the iron residue with water, and returning the washing liquid to crystal dissolution; (4), preparing circulatory alkali liquid with the liquid phase C and crystal-dissolved liquid, adding an acid solution to the remaining crystal-dissolved liquid to adjust pH, and carrying out aluminum-silicon removal, acidifying, crystallizing and separating to obtain sodium dichromate and sodium sulfate; preparing. The process of the invention is simple, the flow is short, and the method is highly operable, low in cost and free of wastewater and is an effective way of chromium salt industry to make recycle use and reduce pollution.