Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for producing chromate by liquid-phase catalytic oxidation of chromite

A liquid-phase catalysis and chromate technology, applied in the direction of chromate/dichromate, etc., can solve the problems of long reaction time and disadvantages

Inactive Publication Date: 2015-04-15
HUBEI ZHENHUA CHEMICAL CO LTD +1
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The above-mentioned patents have different reaction times depending on the oxidant added. When the oxidant is the most commonly used oxygen or air in industrial production, the reaction time is longer, which is not conducive to the implementation of large-scale industrialization.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Chromite ore 250g, chromite ore particle size less than 50μm (-300 mesh), alkali ore ratio 4:1, alkali concentration 60%, manganese hydroxide 125g, lye, chromite and manganese hydroxide are prepared as raw material Slurry was added to the reaction kettle, oxygen was used as an oxidant, the total pressure was controlled to 3.2MPa, the stirring speed was 650 rpm, the temperature was 260°C, the reaction was 120min, and the chromite leaching rate was 90.37%.

Embodiment 2

[0024] 250g of chromite, the particle size of chromite is less than 28μm (500 mesh), the alkali ore ratio is 4:1, the alkali concentration is 60%, manganese hydroxide 12g, the lye, chromite and manganese hydroxide are prepared into slurry , into the reactor, oxygen as an oxidant, control the total pressure of 3.2MPa, stirring speed of 650 rpm, temperature of 260 ° C, reaction 120min, chromite leaching rate of 57.64%.

Embodiment 3

[0028] 250g of chromite, the particle size of chromite is less than 50μm (-300 mesh), the ratio of alkali to mineral is 4:1, the concentration of alkali is 60%, copper oxide is 15g, and lye, chromite and copper oxide are prepared into slurry, Adding oxygen into the reaction kettle, using oxygen as an oxidant, controlling the total pressure to 3.2MPa, stirring speed to 650 rpm, temperature to 260°C, and reacting for 120 minutes, the leaching rate of chromite was 82.53%.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
Granularityaaaaaaaaaa
Login to View More

Abstract

The invention discloses a method for cleanly producing chromate by liquid-phase catalytic oxidation of chromite. The method includes following steps: (1) preparing a slurry material from the chromite, an alkaline solution and a catalyst; (2) performing an oxidizing reaction to the slurry material prepared in the step (1) with an oxidizing agent to obtain a reaction product; (3) diluting the reaction product, performing liquid-solid separation to respectively obtain an alkaline solution and a mixture composed of a crystal of chromate (such as sodium chromate or potassium chromate) and a residue; and (4) dissolving and filtering the mixture and removing impurities from the mixture to obtain a chromate solution, and further performing evaporative crystallization to the chromate solution to obtain the chromate product. The method can effectively increase the efficiency of producing the chromate (such as sodium chromate or potassium chromate) by liquid-phase catalytic oxidation of the chromite. In the method, the catalyst does not enter the liquid phase after the reaction finished so that the catalyst can be separated from the chromate (such as sodium chromate or potassium chromate) product. The catalyst is free of polluting the product so that the method has an excellent industrial application prospect.

Description

technical field [0001] The invention belongs to the field of clean production of chromium compounds, in particular to a method for clean production of chromate by liquid-phase catalytic oxidation of chromite ore. Background technique [0002] The current industrial production methods of chromate mainly include calcium roasting method, calcium-free roasting method and liquid phase oxidation method. In the process of producing chromate with calcium roasting method, a large amount of calcium and chromium slag will be produced. Not only the recovery rate of chromium is about 75%, but also the calcium chromium slag is highly toxic and seriously pollutes the environment; the calcium-free roasting method can effectively Reduce the production and discharge of chromium slag and increase the recovery rate of chromium. However, no matter whether it is roasting with calcium or without calcium, the roasting temperature is above 1000 ° C, the energy consumption of the reaction process is ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C01G37/14
CPCC01G37/14
Inventor 徐红彬石义朗张懿蔡再华付云枫程西川张洋石大学田磊陈小红裴丽丽刘静文
Owner HUBEI ZHENHUA CHEMICAL CO LTD