RU1770426C - Method for processing of dust, formed in tungsten-containing cemented-carbide tool grinding - Google Patents

Abstract

Use: relates to the processing of dust from sharpening carbide tools. SUBSTANCE: dust is treated with ferric iron solution to completely transfer metallic iron from dust to solution. The resulting pudpu is filtered. The precipitate is washed and sulfuric acid leaching of cobalt is carried out. The residue is burned. Tungsten is leached from the cinder with soda solution at T: G. equal to 1: 4, and an excess of soda 200% of stoichiometry per tungsten at 90 ± 5 ° C for 2 hours. Iron, cobalt, tungsten are isolated into independent products.

Description

The invention relates to methods for processing dust from sharpening carbide tools.

A number of methods are known for processing dust from sharpening carbide tools, one of which includes sulfuric acid leaching of iron and cobalt, followed by oxidative roasting of the solid residue and soda leaching of tungsten trioxide.

The main disadvantage of the known methods, including the prototype. - the impossibility of extracting cobalt in an independent phase, and hence, as a consequence, the loss of cobalt during processing. In the prototype, cobalt remains in iron sulfate

It must be said that in the known methods involving acid leaching, it is possible to extract cobalt sulfide concentrate from an acid solution (at pH 2.5-3) by treating the solution with sodium sulfide. However, due to the fact that the Co / Fe ratio in the resulting acidic solutions is

approximately 1 / 60-70, the obtained cobalt concentrates are rather poor (Co 10-12%), and the extraction of cobalt into a poor concentrate from the solution does not exceed 94-96%. Moreover, this technique is not environmentally friendly enough, since hydrogen sulfide is released in the process. Obviously, for a combination of these reasons, this technique did not find industrial implementation.

It should also be noted that the acid solutions obtained in the prototype with a content of g / l and Fe - 60-70 g / l are not suitable for the electrolytic separation of cobalt metal from them.

The aim of the proposed method is to increase the complexity of the use of source dust due to the extraction and transfer of cobalt into an independent phase

The goal is achieved in that the dust is pretreated with a solution of ferric chloride. In this case, as was established experimentally, complete selective leaching of iron to the solution is achieved, while cobalt, which is present in dust as solid

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The primary alloy (WC-Co) does not enter the solution. Further sulfuric acid leaching of the washed precipitate makes it possible to extract cobalt into the independent phase, the sulfuric acid solution.

Example. A portion of dust weighing 500 g of the composition, wt.%: WC 5.9; With 0.5; Fe 36.5; SIC 49.6; others - the rest, was treated with a solution with a concentration of 350 g / l at. After complete iron creation, the resulting pulp was filtered, and the precipitate was washed with water. The washed precipitate was leached at 80 ° C with 20% sulfuric acid at T: W 1: 2.5 for 2 hours. The cobalt recovery in solution was 99.6%, and the cobalt concentration in the solution was 3.14 g / l. The cobalt sulfate solution obtained was further used ten times to leach cobalt from subsequent portions of precipitate washed from iron, resulting in a concentration of cobalt in the solution of 32 g / l. The recovery of cobalt into the solution during the tenth cycle was 96%. This solution (concentrated in cobalt) was used to electrolytically separate cobalt metal from it. The solid precipitate after acid leaching was calcined in air at 650 ° C and treated with a solution of soda (, excess soda - 200% of stoichiometry per tungsten) for 2 hours.

tungsten in the solution from the calcined product was 98.6%. The soda leach sludge, which is a carborundum product, can be used (as in the prototype) for the manufacture of refractories.

Thus, the use of the proposed method makes it possible to recover 98% cobalt in an independent phase, from which metallic cobalt can be isolated by electrolysis, or rich cobalt concentrate is precipitated by other known methods.

Claims (1)

SUMMARY OF THE INVENTION A method for processing dust from sharpening a carbide tool containing tungsten, including sulfuric acid leaching followed by oxidative burning of a solid residue and soda leaching of tungsten trioxide, which involves processing to increase the complexity of processing before the sulfuric acid leaching of the material a solution of ferric chloride with a molar ratio of iron (III) chloride to metallic iron in the starting material is not less than 2: 1 to obtain py with subsequent filtering it, washing the resulting precipitate, and the precipitate was subjected to a sulfuric acid leaching to obtain a solution containing cobalt.