Continuous crystallization system of cobalt sulfate with coarse grain and low water insoluble matters as well as process thereof

Abstract

The invention discloses a continuous crystallization system of cobalt sulfate with coarse grain and low water insoluble matters as well as a process thereof. The continuous crystallization system comprises a filtering machine set, a cooling crystallization set, a discharging set, and connecting pipelines. The continuous crystallization process is as follows: a cooling crystallizer is full of a stock solution or mother liquor, a crystallization circulating pump is opened, cobalt sulphate concentrate which is precisely filtered and a crystallizer supernatant are mixed and enter an external cooler in order to form a supersaturated solution, and the solution enters a crystallizer through a crystallizer guide shell and grows on an original crystal nucleus; cobalt sulfate from an Oslo cooling crystallizer aging zone is discharged and enters a grader, and air drying of cobalt sulfate of coarse grain is directly carried out in order to obtain a qualified cobalt sulfate product; the grader fines enter a thickener, and underflow of the thickener returns the crystallizer and is used as a crystal seed; a part of the thickener overflow returns and is used as a washing lotion for grading, and apart of the thickener overflow is filtered by a filter press and a precision filter and enters an evaporative concentration process. The process has the advantages of good continuity, large proportionof products with coarse grain, low content of water insoluble matters, high crystallization rate, and the like.

Description

technical field [0001] The invention belongs to the technical field of cooling and crystallization of industrial salts, and in particular relates to a continuous crystallization production system of cobalt sulfate with coarse particles and low water insoluble matter and a process thereof. Background technique [0002] At present, the cobalt sulfate crystallization process is routinely cooled by a jacketed crystallization tank, which is suitable for production organizations with small output and no particle size requirements. There are problems such as low production efficiency, small crystal particles, and products that are easy to harden after long-term storage. Especially in recent years, with the development of mechanical automation and the increase of labor costs, it has become a hot spot in the industry to study long-term storage of coarse-grained cobalt sulfate that is not hardened, has good fluidity, and is easy to transport for downstream customers. [0003] ZL201521...

AI Technical Summary

Problems solved by technology

This technology realizes the continuous crystallization production of cobalt sulfate products, but it has the following disadvantages: (1) This technology realizes partial circulation of the cooling water outlet by adding the cooling water storage tank of the tube-and-tube heat exchanger, but it occupies a large area and replaces the The cleaning after the heater is blocked is not considered; (2) The crystals pass through the discharge pump and then enter the centrifugal separation, which will cause friction damage to the particles during the discharge process; (3) The crystallizer with DTB structure, the inside of the guide tube The stirring paddle seriously damages the crystal particle size

The biggest disadvantage of this technology is that vacuum crystallization is carried out after heating the circulating crystallization slurry, which consumes a lot of energy, the end temperature of crystallization is 75°C, the crystallization rate is low, and a vacuum system needs to be prepared, which requires high airtightness of the equipment.

[0006] What is worth noting is that the removal method of cobalt sulfate water-insoluble matter is not involved in the prior disclosed technology

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