Method for removing silicon from phosphogypsum in obverse floatation way under acidic condition

Abstract

The invention relates to a method for removing silicon from phosphogypsum in an obverse floatation way under an acidic condition, comprising the steps of (1) adding waste liquid of pool water of a phosphogypsum stack into phosphogypsum slurry which is washed three times for slurry adjustment during the process of producing phosphoric acid by a wet method to obtain ore pulp at the concentration of pH 1.5-3; (2) properly adding a flotation collector i.e. ether amine salt and a foaming agent i.e. alkyl alcohol; obtaining gypsum concentrate with less than 3% of silica in flotation foam and tailings with rich silica and impurities in flotation bottom flow through the separation processes of one time of roughing, one time of scavenging and two to three times of fine flotation separation; processing the foam and the bottom flow by using a thickening system, a sedimenting system and a separating system to obtain selected gypsum products and byproducts with more silica. According to the method for removing the silicon from the phosphogypsum in the obverse floatation way under the acidic condition, as the floatability difference of the ether amine salt to the gypsum and the silica under a highly acidic condition is fully utilized, a new technology for removing the silica from the phosphogypsum in the obverse floatation way is obtained; the method has the advantages that the processing cost is low, the indexes of a floatation and separation technology are stable, the purity of the selected gypsum products is high, and the requirement on the recycling reutilization of the phosphogypsum can be met.

Description

technical field [0001] The invention relates to a method for positive flotation desiliconization of phosphogypsum under acidic conditions, in particular to a production method for removing silicon dioxide by sorting phosphogypsum as a by-product of phosphoric acid in a wet process. It belongs to the field of reuse of by-product resources. Background technique [0002] During the production process of wet-process phosphoric acid, every ton of phosphoric acid (100P 2 o 5 %) produces about 4.5-5.5 tons of phosphogypsum. With the development of the domestic high-concentration phosphorus compound fertilizer industry, the current on-site stockpile of phosphogypsum has reached 300 million tons, and is increasing at a rate of 50 million tons per year. Since the phosphogypsum by-product of wet-process phosphoric acid is highly acidic (pH 1.5~2), long-term stockpiling will damage the ecological environment, which directly affects the sustainable development of the high-concentration...

AI Technical Summary

Problems solved by technology

In the processing of gypsum building materials, excessive silica content will lead to unstable product quality, small product market capacity, and small resource reuse scale; Higher, will lead to the production of cement products not up to standard, unable to run for a long time

Images