Method for removing iron from leachate of nickel oxide ores

Abstract

The invention discloses a method for removing iron from leachate of nickel oxide ores, which comprises the following steps of: (1) adding a certain amount of water into a reaction kettle; (2) heating to the temperature of between 70 and 100 DEG C, and under the condition of stirring, introducing the leachate of the nickel oxide ores at flow speed of between 0.005 and 0.05 L / minute for 0.5 to 4 hours and the leachate of the nickel oxide ores at the flow speed of between 0.005 and 0.1 L / minute for 0.5 to 4 hours to react the leachate with an oxidant; and (3) stopping adding the leachate of the nickel oxide ores and the oxidant, stirring to react for 15 to 90 minutes, and filtering slurry to obtain filter liquor, namely solution from which the iron is removed. Compared with the prior art, in the method, an aim of removing the iron is fulfilled without adding reducers and alkaline materials, so a process is simplified, and the production cost is reduced; in the process of removing the iron, precipitates have the excellent performance and also can be directly sold as products, so the economic benefit in the process of removing the iron is improved; and the loss of valuable metal such as nickel, cobalt and the like in the process of precipitating the iron is almost zero.

Description

technical field [0001] The invention relates to a method for removing iron from a nickel ore leachate, in particular to a method for removing iron from a nickel oxide ore leachate. Background technique [0002] As the global demand for nickel products continues to rise, the development of nickel ore resources has become an urgent task. Nickel oxide ore is the main resource of nickel ore, and the acid leaching process is a common technology for smelting nickel oxide ore. The leaching solution obtained by atmospheric acid leaching or high-pressure acid leaching contains metal ions such as iron, nickel, cobalt, magnesium, aluminum, etc. Only by purifying and separating the leaching solution can pure nickel, cobalt, magnesium, aluminum, iron, etc. be obtained. Metal or metal-containing salt compounds. Usually the concentration of iron ions in the leachate is higher than that of other metal ions, so the first step in most purification and separation processes is to remove iron....

AI Technical Summary

Problems solved by technology

Fe 3+ The reaction of hydrolysis to goethite requires Fe in solution 3+ The concentration is low enough, such as less than 1g / L, and Fe in the nickel oxide ore leachate 3+ The concentration is often higher than this value, so it is necessary to add a reducing agent to remove part of the Fe 3+ reduced to Fe 2+ ; 3+ The hydrolysis reaction is also required to be carried out at a lower acidity (such as a pH value of 2 to 5). The acidity of the nickel oxide ore leachate obtained by the acid leaching process is generally higher, and usually the pH value is less than 1 or around 1, which requires Adding alkaline substances to adjust the acidity of the solution, but adding alkaline substances can easily cause some Fe 3+ It is preferentially deposited in the form of iron hydroxide, which will cause the loss of metal ions such as nickel and cobalt and difficulty in filtration; in addition, if the goethite particles generated by hydrolysis are too fine, the fine goethite particles will pass through the filter cloth when the solution is filtered, which will cause As a result, the solution is not filtered clean, and goethite products are difficult to recycle; if the crystallinity of goethite produced by hydrolysis is not high, metal ions such as nickel and cobalt will also co-deposit with goethite, resulting in the loss of nickel and cobalt elements

[0005] In the reported iron removal methods, most of them need to use lye to adjust the acidity of the leaching solution and add a reducing agent to carry out the iron removal operation. Therefore, the iron precipitation process will inevitably lead to the loss of valuable metals such as nickel and cobalt and the difficulty of filtering the pulp.