A method for saving energy and reducing consumption by alkali leaching of scheelite

Abstract

The invention discloses an energy-saving and consumption-reducing method for alkaline leaching of scheelite. The method comprises the following steps: (1), processed scheelite concentrates are placed in a slurry barrel, and then concentrated alkali liquor, an auxiliary reagent and sodium hydroxide are added; (2), prepared slurry is pumped into a jacket-free high-pressure leaching kettle, steam is introduced directly, the mixture is subjected to heat preservation for a period of time, and a stirring reaction is stopped; (3), pressure relief is performed, the slurry is discharged into a slurrying tank, water is injected, slurrying and filtering are performed, primary filtrate flows into a strong liquor storage tank, filtering residues are washed with hot water continuously, and washing liquor and the strong liquor are stored separately; (4), a solution in strong liquor storage tank is pumped into a three-effect concentration evaporator, a raw material port is used for a third-effect stage, a discharging port is used for a first-effect stage, a feed liquid at an outlet flows into a single-effect jacketed crystallization boiler to be concentrated continuously, and a steam valve is closed for material discharge; (5), solid-liquid separation is performed, filtered alkali liquor returns to a ball mill for blending of slurry and alkali, and crystalline powder is delivered to a dissolution tank to be dissolved and diluted for ion exchange. According to the method, electric heating is changed into direct steam heating, energy is saved, the production efficiency is high, a multi-effect evaporator is adopted to recover residual alkali, energy consumption is reduced greatly, and the alkali recovery rate is increased.

Description

technical field [0001] The invention relates to tungsten hydrometallurgy, in particular to a method for saving energy and reducing consumption by alkaline leaching of scheelite. Background technique [0002] my country is a country rich in tungsten resources, and tungsten resources mainly exist in the form of wolframite and scheelite. With the decreasing amount of wolframite resources, mining scheelite resources has become the main mineral in the tungsten industry. In the past, scheelite was a difficult-to-select and difficult-to-smelt raw material, and scheelite resources still remained in the calculation of resource reserves. With breakthroughs in scheelite beneficiation and smelting technology, vigorous development of scheelite has become the mainstream. The pressure leaching process using high temperature and excess alkali can also obtain a good leaching rate (relative to wolframite leaching). In recent years, the production capacity and scale of scheelite smelting have...

AI Technical Summary

Problems solved by technology

The process equipment of alkali recovery enterprises in the industry mainly uses jacketed evaporators for evaporation and concentration. The biggest disadvantage of this equipment is that the energy consumption is very high. It is precisely because many enterprises feel that the energy consumption of alkali recovery is high, and the unit cost of alkali recovery is high. The income is low, it is better to use sodium hydroxide directly, so that the popularization and application of alkali recovery process is less

Images