Integrated treatment method and device of titanium chloride dreg filtrate membrane

Abstract

The invention relates to an integrated treatment method and device of titanium chloride dreg filtrate membrane and belongs to the chemical industry field of titanium white. The technology comprises the following steps: step 1: preparing titanium chloride dreg filtrate; step 2: regulating the pH (Potential of Hydrogen); step 3: carrying out primary reverse osmosis concentration; step 4: carrying out primary nano-filtration membrane impurity removal; step 5: carrying out secondary reverse osmosis concentration; step 6: carrying out secondary nano-filtration membrane impurity removal. The technology provided by the invention aims at concentrating and purifying sodium chloride saline water in the titanium chloride dreg filtrate; low-concentration sodium chloride saline water obtaining heavy metal ions is purified into high-concentration light saline water for a chlorine alkali industry through the technology of integrated membrane seperation, pH regulation, precipitation and sulfate radical removal, so that chlorination-process titanium chloride dreg is completely subjected to harmless treatment and zero emission of treatment of technological solid waste residues is realized; the technology has a remarkable environmental protection effect on a chlorination-process titanium chloride production process and resources in the waste residues can be also efficiently utilized; the technology has remarkable social and environmental benefits.

Description

technical field [0001] The invention relates to a membrane-integrated treatment method for titanium chloride slag filtrate, in particular to a new process for concentrating and purifying sodium chloride in titanium chloride slag filtrate by using membrane separation and resin integration technology, belonging to the field of titanium dioxide chemical industry. Background technique [0002] At present, the methods for producing titanium dioxide mainly include sulfuric acid method and chloride method. Due to the long process of the sulfuric acid method, serious pollution and poor product quality, it was gradually replaced by the chlorination method. [0003] In the current production of titanium dioxide by chloride method, its main process is: [0004] a. Mix titanium raw material (such as: high titanium slag) and reducing agent (such as: petroleum coke) evenly, then send it into the chlorination furnace, and feed chlorine gas to carry out boiling chlorination at a temperatur...

AI Technical Summary

Problems solved by technology

However, the membrane technology used is too simple, and there are several problems as follows: one is that the nanofiltration membrane alone cannot concentrate brine; the nanofiltration membrane is effective in removing ions above divalent, but it cannot intercept monovalent chloride ions , so that the brine cannot be concentrated. The brine treated directly with the nanofiltration membrane not only has a low concentration, but also a large amount, which is not conducive to the water balance of the chlor-alkali process; the second is the accumulation of sulfate ions. The root ion content is very small, only 20-50mg / L, but from the perspective of the entire patented process, there is no way out for the sulfate ion. The more it accumulates, it will form heavy metal sulfate precipitation with barium ions or strontium ions when the nanofiltration reaches a certain level, which will affect the membrane process; the third is that the water entering the nanofiltration membrane is alkaline, which directly lays the groundwork for the smooth progress of the nanofiltration process. The source of the danger, because the nanofiltration membrane intercepts ions with a divalent or higher value, and heavy metal ions with a higher than a divalent price will accumulate more and more, and it is very easy to produce precipitation under alkaline conditions and affect the progress of the membrane process. Therefore, it is also necessary to carry out deal with

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