Where is potassium dichromate

A kind of production method of potassium bichromate Technical field. The present invention relates to a kind of production method of dichromate, particularly relate to method by potassiumchromate cleaner production potassium bichromate. Potassium bichromate claims arsenic potassium again, and molecular formula is K 2 Cr 2 O 7 , be a kind of important chromaking chemical product. Be mainly used in chromic salts products such as preparation chromium sesquioxide, potassium chromium sulfate and chrome yellow, also be used to make products such as match, explosive, electroplating additive, mordant dyeing, tanning agent, medicine, oxygenant, synthetic perfume, enamel porcelain glaze powder, metal passivator, printing-ink and welding electrode.

The industrial production potassium bichromate mainly adopts sodium dichromate 99 and Repone K metathesis process at present, and its chemical equation is:. The chemical main reaction formula of chromite oxidation-sodium roasting is:. The chemical equation of alkalescence Sodium chromate sulfuric acid acidation is:. Or as U.

Adopt above-mentioned produced in conventional processes sodium dichromate 99, the utilization ratio of chromium is low in the chromite, and can produce and contain high toxicity chromium waste residue and sodium pyrosulfate in a large number, and environmental pollution is serious, by the state key monitoring trade.

Chromite salt of wormwood roasting method be with chromite with carry out high temperature oxidation roasting after salt of wormwood, Wingdale mix and make potassiumchromate, the water logging rear filtrate makes it change potassium bichromate into sulfuric acid acidation or carbonic acid gas carbonating. With in the potassium bicarbonate solution and removal of impurities, neutral solution sulfuric acid acidation potassium bichromate, main chemical equation is:.

Chromite salt of wormwood roasting method and Ke Xingjia roasting method production potassium bichromate all exist in the chromite chromium utilization ratio low, potassiumchromate intermediate separation difficulty, production process energy consumption height, contain high toxicity sexavalent chrome waste residue, discharge amount of exhaust gas is big, environmental pollution is serious, problems such as potassium bichromate product cost height, thereby limited the large-scale industrial application of aforesaid method.

The defective that the objective of the invention is to overcome that the environmental pollution that existing potassium bichromate production method exists is serious, the chromium utilization ratio is low and by product can't utilize again in the chromite, thus a kind of clean preparation method with potassium bichromate of industrial operation is provided.

The production method of dichromate provided by the invention is that the inferior fused salt liquid phase oxidation of chromite chromic salts new cleanproduction process is produced the product engagement technique of potassiumchromate method, and its principle is to adopt CO 2 Gas is carbonization potassiumchromate production potassium bichromate under the low pressure condition, and its chemical equation is as follows:.

Then during the potassiumchromate in separating potassium bicarbonate solution, utilize potassiumchromate in saturated potassium hydrogen carbonate solution, to have big solubleness, and potassiumchromate has tangible salting out to saleratus, and this salting out increases along with the reduction of temperature, the present invention proposes a kind of novel method that is different from traditional pyrolysis evaporation technology and reclaims potassiumchromate. This method elder generation enrichment carbonation reaction is finished the potassiumchromate concentration of liquid, the method that adopts cooling to saltout is isolated the saleratus crystal from solution then, this crystal can make qualified technical grade saleratus product after recrystallization, countercurrent washing, realize the renewable resources utilization of potash; The high dense potassium chromate solution that separates the back gained returns slurry carbonation preparation potassiumchromate stock liquid.

This method is a kind of cleaning method of potassiumchromate production potassium bichromate. The objective of the invention is to be achieved through the following technical solutions:. The invention provides a kind of production method of dichromate, by potassiumchromate crystal K 2 CrO 4 production potassium bichromate K 2 Cr 2 O 7 , this method comprises that with potassiumchromate slurry carbonating the potassium bichromate crystal of gained is made with extra care by back deironing and aluminium impurity process, and the gained potassium bicarbonate solution is saltoutd through cooling, reclaims potassiumchromate and coproduction saleratus, and it comprises the steps:.

Described step 2 souring agent comprises potassium bichromate or chromic trioxide. Compare with the technology of prior art production potassium bichromate, the production method of potassium bichromate provided by the invention has tangible advantage:.

Below by further setting forth this implementation of processes process and step in conjunction with the accompanying drawings and embodiments.

Feed CO continuously 2 Gas carries out the slurry carbonation reaction to 0. All the other are moisture content. Chromic trioxide is Henan Province development chemical industry group industry top grade product. Adopt 1. SO 4 Chromium is also used as a component in leather shoes, suede, upholstery and fur tanning agents, wood preservatives, anti-corrosion paints, fire retardants, printing inks, color glazes, chromium pigments, dark textile dyes, concrete, epoxy hardeners, and photographic color developer.

Chromate is also found in cement not dried and metal plating and is a cause of occupational dermatitis in bricklayers, construction workers, and metal workers. For additional information about products that might contain Potassium dichromate , visit the Household Products Database online at the United States National Library of Medicine. These lists are brief and provide just a few examples. They are not comprehensive. Product formulations also change frequently.

Read product labels carefully and talk to your doctor if you have any questions.