Method for recovering sodium carbonate from sodium tungstate leaching solution

A technology from sodium tungstate and sodium carbonate, applied in the direction of alkali metal carbonate, chemical instruments and methods, tungsten compounds, etc., can solve the problems of high production cost and environmental pollution, improve recovery rate, reduce cost, realize The effect of industrial production

Active Publication Date: 2019-05-31
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The purpose of the present invention is to provide a method for reclaiming sodium carbonate from sodium tungstate leaching solution, realize the recycling of sodium carbonate, and solve the problems of environmental pollution and high production cost

Method used

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  • Method for recovering sodium carbonate from sodium tungstate leaching solution

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Embodiment 1

[0032] A kind of method that present embodiment reclaims sodium carbonate from sodium tungstate leaching solution, comprises the steps:

[0033] Step 1, evaporation and concentration:

[0034] Take 2000ml containing WO 3 40g / L, Na 2 CO 3 / WO 3 (mass concentration ratio) = 1.0 sodium tungstate leaching solution, concentrated by evaporation to a solution volume of 500ml, which contains WO 3 160g / L, containing Na 2 CO 3 160g / L, obtain concentrate I;

[0035] Step 2, freeze crystallization:

[0036] Cool the concentrated liquid I. When the temperature drops to 25°C, add 62g of crushed ice while stirring. After the crushed ice is completely dissolved within 3 minutes, the temperature drops to 16°C. After -1°C, continue to keep warm for 2.0 hours, and obtain sodium carbonate crystals and crystallization mother liquor after filtration, wherein the sodium carbonate crystals contain Na 2 CO 3 33%, containing WO 3 1.2%, Na in crystallization mother liquor 2 CO 3 / WO 3 (...

Embodiment 2

[0040] A kind of method that present embodiment reclaims sodium carbonate from sodium tungstate leaching solution, comprises the steps:

[0041] Step 1, evaporation and concentration:

[0042] Take 2000ml containing WO 3 110g / L, Na 2 CO 3 / WO 3 (mass concentration ratio) = 0.7 sodium tungstate leaching solution, concentrated by evaporation to a solution volume of 1000ml, which contains WO 3 220g / L, containing Na 2 CO 3 154g / L, obtain concentrate I;

[0043] Step 2, freeze crystallization:

[0044] Cool the concentrated solution I, when the temperature drops to 10°C, adjust the rotating speed to 6 rpm, continue to freeze and cool down to 0°C, add 30g of sodium carbonate crystals as a seed crystal, and continue to insulate for 1.5 hours, and obtain Sodium carbonate crystals and crystallization mother liquor, wherein sodium carbonate crystals contain Na 2 CO 3 32%, containing WO 3 1.9%, Na in crystallization mother liquor 2 CO 3 / WO 3 (mass concentration ratio) dro...

Embodiment 3

[0048] A kind of method that present embodiment reclaims sodium carbonate from sodium tungstate leaching solution, comprises the steps:

[0049] Step 1, evaporation and concentration:

[0050] Take 2000ml containing WO 3 96g / L, Na 2 CO 3 / WO 3 (mass concentration ratio) = 1.5 sodium tungstate leaching solution, concentrated by evaporation to a solution volume of 1400ml, which contains WO 3 137g / L, containing Na 2 CO 3 206g / L, obtain concentrate I;

[0051] Step 2, freeze crystallization:

[0052] Cool the concentrated liquid I, when the temperature drops to 15°C, adjust the rotating speed to 15 rpm, continue to freeze and cool down to 5°C, and continue to keep warm for 1.0 hour, after filtration, sodium carbonate crystals and crystallization mother liquor are obtained, of which sodium carbonate Crystal contains Na 2 CO 3 34%, containing WO 3 0.9%, Na in crystallization mother liquor 2 CO 3 / WO 3 (mass concentration ratio) drops to 0.36, and the crystallization...

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Abstract

The invention discloses a method for recovering sodium carbonate from a sodium tungstate leaching solution, andbelongs to the field of resource recycling.Aiming at a feature that a concentration of WO3 in the sodium tungstate leaching solution is lower generally, the method comprises the following steps of: firstly, concentrating the sodium tungstate leaching solution, improving an initial concentration of Na2CO3 in the solution as much as possible to improve a crystallization rate of the sodium carbonate in a freezing crystallization process, and simultaneously ensuring a proper initial concentration of WO3 to prevent the sodium tungstate from crystallizing together with the sodium carbonate.By the adoption of the method for recovering the sodium carbonate from the sodium tungstate leaching solution,a direct freezing crystallization method is combined with an NaHCO3 crystallization method, most of sodium carbonate crystal are recovered by the direct freezing crystallization method, thereby reducing the consumption of subsequently-injected CO2 and neutralization time of ventilation, meanwhile, further improving a total recovery rate of the sodium carbonate through the NaHCO3 crystallization method, and covering the shortage of low recovery rate of the direct freezing crystallization method; and aiming at the feature that temperature-lowering is slow in a later period in a cooling and temperature-lowering process, crushed ice blocks are directly added to dissolve and rapidly lower the temperature, thereby greatly improving the productioneffectiveness.

Description

technical field [0001] The invention belongs to the field of resource recovery and utilization, in particular to a method for recovering sodium carbonate from sodium tungstate leaching solution. Background technique [0002] In the tungsten metallurgical industry, it is a very common production process to use sodium carbonate to leach tungsten minerals or tungsten waste containing tungsten oxide, such as leaching scheelite ore with sodium carbonate under high pressure or leaching waste containing tungsten after high-temperature roasting with sodium carbonate Catalyst, tungsten shavings, tungsten carbide powder, etc. will all get sodium tungstate leaching solution. [0003] The amount of sodium carbonate used in the leaching process is much higher than the theoretical amount, so the sodium tungstate leaching solution often contains excessive sodium carbonate, limited by the characteristics of the sodium carbonate leaching process, the leaching solution contains WO 3 Generall...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01D7/24C01G41/00
Inventor 霍广生蒲海鹏易新涛刘辉郭磊马顺曾璐琦朱和平
Owner CENT SOUTH UNIV
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