Method for refining sodium sulfate powder from chromium-containing mirabilite

A technology of Glauber's salt and Yuanming powder, applied in chemical instruments and methods, alkali metal sulfites/sulfites, alkali metal compounds, etc., can solve problems such as failure to realize industrialized production, limited application, difficult transportation, etc.

Active Publication Date: 2014-01-29
SICHUAN YINHE CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Since the by-product Glauber's salt contains a small amount of hexavalent chromium, its application is limited
In the past, some people tried to dissolve Glauber's salt to remove chromium and evaporate it to make Yuanming powder. Because the cost is higher than that of products made from natural Glauber's salt, industrial production has not been realized.
At present, the processing methods of chromium-containing Glauber's salt in my country's chromium salt factory ge

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0056] Step 1: 500 kg of chromium-containing Glauber's salt with a sodium sulfate content of 80.00 wt %, a hexavalent chromium content (calculated as sodium peruminum) of 0.05 wt % and a water content of 19.50 wt % from the process of preparing sodium peruminate by sulfuric acid method is wet-ground in the presence of water Slurry, the particle size control after wet milling is more than 120 orders, obtains the aqueous slurry of 650 g / liter. Use 98wt% sulfuric acid to adjust the aqueous slurry to pH = 2.5, then add 0.23 kg of sodium sulfite for reduction to obtain a supersaturated aqueous solution of sodium sulfate. Then the reaction mixture was naturally cooled to room temperature at a stirring rate of 45 rpm, during which crystals were continuously precipitated.

[0057] The crystals were then filtered out using a vacuum belt filter, which were referred to as primary crystals. This crystal is washed with the saturated aqueous solution newly prepared by sodium sulfate and wa...

Embodiment 2

[0061] Step 1: 500 kg of chromium-containing Glauber's salt with a sodium sulfate content of 80.00 wt %, a hexavalent chromium content (calculated as sodium peruminum) of 0.05 wt % and a water content of 19.50 wt % from the process of preparing sodium peruminate by sulfuric acid method is wet-ground in the presence of water Slurry, the particle size control after wet milling is more than 120 orders, obtains the aqueous slurry of 650 g / liter. Use 98wt% sulfuric acid to adjust the aqueous slurry to pH = 1.0, then add 0.35 kg of sodium sulfite for reduction to obtain a supersaturated aqueous solution of sodium sulfate. Then the reaction mixture was naturally cooled to room temperature at a stirring rate of 45 rpm, during which crystals were continuously precipitated.

[0062] The crystals were then filtered out using a vacuum belt filter, which were referred to as primary crystals. This crystal is washed with the saturated aqueous solution newly prepared by sodium sulfate and wa...

Embodiment 3

[0066]Step 1: 500 kg of chromium-containing Glauber's salt with a sodium sulfate content of 80.00 wt %, a hexavalent chromium content (calculated as sodium peruminum) of 0.05 wt % and a water content of 19.50 wt % from the process of preparing sodium peruminate by sulfuric acid method is wet-ground in the presence of water Slurry, the particle size control after wet milling is more than 120 orders, obtains the aqueous slurry of 650 g / liter. Use 98wt% sulfuric acid to adjust the aqueous slurry to pH = 2.0, then add 0.32 kg of sodium sulfite for reduction to obtain a supersaturated aqueous solution of sodium sulfate. Then the reaction mixture was naturally cooled to room temperature at a stirring rate of 45 rpm, during which crystals were continuously precipitated.

[0067] The crystals were then filtered out using a vacuum belt filter, which were referred to as primary crystals. This crystal is washed with the saturated aqueous solution newly prepared by sodium sulfate and wat...

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Abstract

The invention relates to a method for refining sodium sulfate powder from chromium-containing mirabilite. The method comprises the following steps: a) grinding the chromium-containing mirabilite in the presence of water to prepare water-containing slurry; b) regulating the pH of the water-containing slurry obtained in the step a) with sulfuric acid to 2-3, and then adding sodium sulfite to reduce hexavalent chromium in the water-containing slurry to trivalent chromium, thus obtaining a saturated or over-saturated sodium sulfate water solution; c) stirring and crystallizing the saturated or over-saturated water solution which is obtained after reduction in the step b); d) filtering out crystals obtained in the step c); e) washing the crystals obtained in the step d) with the saturated sodium sulfate water solution; f) re-crystallizing the washed crystals obtained in the step e) with a saturated neutral sodium sulfate water solution to obtain the sodium sulfate powder. According to the method provided by the invention, additional heating is not required, the energy consumption is low, the obtained sodium sulfate powder has high yield and high purity, the content of sodium sulfate can achieve 99.00-99.90wt%, and the chromium content does not exceed 5ppm.

Description

technical field [0001] The present invention relates to a kind of method of refining Yuanming powder by chromium-containing Glauber's salt, more specifically, relate to a kind of method that utilizes chromium-containing Glauber's salt to refine Yuanming powder under low-temperature saturated or supersaturated solution state (hereinafter sometimes also referred to as "YH "Law). Background technique [0002] The production scale of my country's sodium sulfate ranks first in the world. The raw materials mainly include salt lake mirabilite, seawater sun-dried mirabilite, mirabilite ore and industrial by-products. The current production methods mainly include four-effect vacuum evaporation of nitric acid, secondary steam waste heat nitric acid production method, Five-effect vacuum evaporation production method, full-solubility evaporation dehydration production method, etc. These production processes are made into finished products through processes such as raw material dissoluti...

Claims

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Application Information

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IPC IPC(8): C01D5/00
Inventor 李先荣马顺友白礼太胡义华
Owner SICHUAN YINHE CHEM
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