CS256859B1 - A method for producing antimagnetic nickel oxide - Google Patents

Abstract

The solution relates to the chemical treatment of nickel oxides. Until now, unwanted impurities - mostly nickel metal - have been removed from the ground nickel oxides by leaching with nitric acid. This chemical treatment brings many disadvantages in the investment area and environmental protection. A novel method of removing undesirable impurities is proposed, which consists in treating nickel oxides by milling and single-stage or multi-stage magnetic separation. The product of the treatment is nickel oxide of the required purity. The solution can be used in those processes where unwanted magnetic impurities are removed from the nickel oxides.

Description

The object of the invention is a method of removing magnetic particles, in particular metallic nickel, from nickel oxides by magnetic separation.

The prior art methods of removing magnetic particles from nickel oxides are based on the principle of metallurgical and leaching methods. The removal of magnetic particles is most often carried out with nitric acid. A disadvantage of these processes is the formation of gaseous fumes containing a high concentration of nitrogen oxides which are released into the atmosphere. These are undesirable exhalations due to their high toxicity. The main disadvantage of the leaching methods is that they do not make it possible to produce antimagnetic nickel oxide from oxides with a high magnetic particle content. With higher content of these particles, already above 5%, the consumption of nitric acid increases and the reaction is considerably exothermic, often overflowing with the possibility of chemical burns. Another disadvantage is the need to build up nitric acid storage tanks and conveying routes for the processing of dilute solutions of waste nickel nitrate. These circumstances make the described process uneconomical.

The above-mentioned disadvantages of separating the magnetic particles from the nickel oxides are eliminated by the method according to the invention, which consists in separating the magnetic particles from the nickel oxide suspension by 1-10 fold magnetic separation. The magnetic separation necessarily precedes the corresponding degree of grinding of the nickel oxide feedstock to be processed.

The advantage of the invention is that all kinds of nickel oxides with a high content of magnetic fractions can be processed with much higher productivity and economy. Another advantage of the treatment of the nickel oxides according to the invention is the possibility of significantly increasing production without further induced investment.

The separated magnetic part with a high content of metallic nickel can be advantageously processed in the production of nickel salts or in metallurgy.

DETAILED DESCRIPTION OF THE INVENTION the following examples.

He did

160 kg of nickel oxides with a magnetic particle content of 13% by weight are introduced into a ball mill, 1800 liters of water are added and the mixture is milled for 24 hours. The suspension is pumped into a container equipped with a stirrer. From there, the slurry flows by gravity to a permanent wet magnetic separator which operates at a magnetic induction value of 0.23 Tesla on the drum surface. A triple magnetic separation is performed, with the first separation cycle decreasing the content of magnetic particles in the non-magnetic fraction from the original 12 4 to 2 4, the second separation to 0.8% and the third to 0.2%, which corresponds to PND 50 / 618-81. The duration of one separation cycle is 15-60 minutes at the indicated amount of input.

Example 2

160 kg of nickel oxides with a magnetic particle content of 8% by weight are placed in a ball mill, 1800 liters of water are introduced and the mixture is ground for 24 hours. The slurry is further pumped into the reservoir and flows by gravity into the magnetic separator of Example 1. A four-fold magnetic separation is performed, each for 20-60 minutes. The resulting contents of the magnetic particles in the non-magnetic fraction are

AFTER 1. separaci P ° 2. separaci P ° 3. separaci after 4. separaci

1.8% magnetic particles 0.4% magnetic particles 0.2% magnetic particles 0.2% magnetic particles

Example 3

The operationally ground nickel oxide sample of the example is subjected to wet electromagnetic separation. The separation takes place under the following conditions:

magnetic induction filling of separating zone filling zone with cotton load zone velocity of suspension suspension concentration of suspension

0.5 Tesla stainless steel wool with a volume% g diameter per cm zone volume mm / s

300 g / l fiber 150 microns

The content of magnetic particles decreased from the original 8 in the proportion after the single-stage separation.

0.1 wt% in non-magnetic

Claims (2)

OBJECT OF THE INVENTION A process for the production of antimagnetic nickel oxide, characterized in that the nickel oxides with a magnetic particle content of 0.21% to 30% by weight after wet grinding are subjected to magnetic separation. Method according to Claim 1, characterized in that, depending on the amount of magnetic particles in the starting nickel oxides, a magnetic separation of 1 to 10 times, preferably 3 to 4 times, is carried out.