KR890002035B1 - Leaching method of ni from the low fineness ore - Google Patents

Abstract

Extraction of nickel from the low quality laterite ore is effected by leaching electrochemically in the electrolysis bath with a separator between cathod chamber and anode chamber. Nickel is recovered from 0.01-10.0 mol. sulfuric acid solution with blowing the sulfurous acid gas. Also anode chamber consists of 0.01-10.0 mol. sulfuric acid solution including source ore powder under 10 mesh.

Description

Leaching of nickel from low grade larelite

The present invention relates to a method of leaching and recovering nickel by wet smelting from a low-grade lareite, which is a nickel ore, which is largely present in the world, and an object thereof is to efficiently process low-grade ore.

In general, the method of leaching nickel from nickel ore should be different depending on the kind and grade of ore. However, due to the depletion of high grade light, there is a great interest in the treatment of low quality larelite ore with low nickel quality (less than 2% nickel content). It is concentrated.

To date, several methods of treating low quality larelite have been developed and are in experimental stages or have been applied in actual plants.

Representative methods include sulfuric acid leaching and reducing roast-ammonia leaching.

Sulfuric acid leaching (ETcarlson and CSSimons, Jom. Mar., 1960, pp. 206-213) is being used in Moa Bay, Cuba, which pulverizes laterite ores with high iron content. The nickel was eluted by pressure extrusion with sulfuric acid at about 240 ℃. Iron is made of goethite or hematite.

However, this method is limited to ore with a low magnesium content because the consumption of sulfuric acid in the ore increases the consumption of sulfuric acid, the selective leaching effect of nickel is poor, and the post-treatment of the leaching liquor is not easy.

Unlike sulfuric acid leaching, the ammonia leaching method is applied regardless of the kind of ore. Currently, Nicaro, Cuba (see MMCaron.Trans.AIME, 188 P 67, 1950), and Nonock, Philippines ( Nonoc) (see T. Harada et al., JMMI of Japan, 98, P 105, 1981), and North Queensland (Australia, JGReid, International Laterite Symp., AIME, P 368, 1979). have.

In this method, fine metallic nickel obtained by mixing non-sulfide nickel ore such as finely divided laterite with a small amount of carbon particles and reducing it at 700-800 ° C. with a reducing gas is leached into an ammonia solution.

In addition, as a technique at an experimental stage, a segmentation method has been developed, but this method has not yet reached the practical stage.

This method mixes 5-10% chloride (Nacl, CaCl ₂ ) with 4-8% carbon particles and roasts them in an inert or reducing atmosphere at 850-1000 ℃ to selectively deposit metal nickel on the surface of carbon particles. It is a method of recovering nickel concentrate by physical screening method such as barge or charity and then leaching metal nickel with ammonia solution.

This method has the advantage of selectively leaching nickel even if iron or magnesium is contained in the ore, but the processing steps such as the process of roasting low-grade ore at high temperature, concentration process and leaching process are not only complicated, but also require enormous fuel costs. There is a disadvantage.

As described above, both conventional wet treatment methods such as high temperature and high pressure, and reduction roasting-ammonia leaching at high temperature have been found to have almost no economic feasibility in low-grade laterite light treatment.

Therefore, the present invention avoids the conventional inefficient treatment method, especially in the low-grade nickel larerite ore treatment, in which the low-grade larerite ore is directly leached and recovered by recovering nickel in the ore in the solution by electrochemical method. In view of this, the low quality larelite can be treated in a very simple process to economically leach and recover nickel.

The present invention will be described in detail as follows.

The low-grade Larerite ore, which is about 1.0-2.0% Ni, is polished with -100 mesh, made into 0.01-10.0M sulfuric acid solution, and filled in the cathode chamber of the electrolytic cell with a separator. While sulfuric acid (S0 ₂ ) gas is injected into a saturated solution, it is electrolyzed for 10-100 minutes to leach nickel.

In this case, 0.01-10.0 M sulfuric acid solution is used as the positive electrolyte. As the conditions at the time of electrolytic leaching, sulfite gas is sufficiently injected at room temperature. In addition, the potential of the cathode is maintained at -0.1 to 5.0 volts with respect to the saturated calomel electrode.

Thus when leaching deliver the laterite in the cathode chamber containing a main component of the ores of nickel hydroxide [(Fe, Ni) O ( OH), nH 2 O] The acidic solution when three gacheol is easily reduced leaching in two gacheol by SO ₂ Ni The acid is ionized and leached.

As described above, the present invention is a simple method of directly electrolytic leaching of a low-grade nickel laterite mineral liquid, and has a very low treatment cost compared to the conventional sulfuric acid leaching at high temperature and high pressure or the roasting reduction-ammonia leaching at 700-800 ° C. It is economical.

The actual amount of electricity consumed is 140-200 kwh / raw ore tons, compared to the electricity required in the furnace refining (600-800 kwh / raw ore ton), it can be seen that it is significantly economical.

Example 1

Take 200gr. Of low-grade Indonesian Larelite ore with the chemical composition as shown in Table 1, polish it with about -100 mesh, dissolve KI 83gr. Mixed in 1 liter of 0.5M sulfuric acid solution, put it in the cathode chamber of the electrolytic cell, and then Sulfurous acid gas is passed through at a flow rate of about 100 ml / min. For 30 minutes.

The anode chamber is filled with 1 liter of 0.5 M sulfuric acid solution.

TABLE 1

A platinum electrode was installed in the electrolytic cell filled with the anolyte and the catholyte as described above, and the cathode potential was kept at -1.0 volts (S.C.E) while injecting sulfurous acid gas into the cathode chamber, and leached for 90 minutes. At this time, the leaching rate of nickel in ore was about 66.3%.

Example 2

Take 20gr of Indonesian low-grade Larerite ore with chemical composition as shown in Table 2, and grind it to about -100 mesh, mix it with 200ml of 0.25M sulfuric acid solution, fill it in the cathode chamber of the drying tank, and then dissolve sulfuric acid gas in the cathode chamber about 80ml / Inject at a flow rate of min.

At this time, the anode chamber is filled with 200 ml of 0.25M sulfuric acid solution.

TABLE 2

In this state, in the same manner as in Example 1, when leaching at the negative electrode potential of −0.8 volts (S.C.E) for 60 minutes, the leaching rate of nickel was about 63.4%.

Example 3

20g of low-grade laterite ore from Indonesia having the chemical composition shown in Table 3 was taken and electrolytic leached at the negative electrode low -0.7 volts (S.C.E) for 50 minutes in the same manner as in Example 2, where the dml nickel sedimentation rate was 52.9%.

TABLE 3

Table 4 shows the recoveries of nickel when tested with the same sample according to the method according to the present invention and the treatment method of low-grade larerite light by the conventional aggregation roasting-floating light-ammonia leaching method. As can be seen from the table, the recovery rate of the two methods is high or low depending on the sample. However, in the treatment step, the method of the present invention is simple in one step compared to the conventional method in the three step step. In addition, since operating at room temperature, the treatment cost can be very reduced, and the present invention can effectively and economically treat low-grade larerite.

TABLE 4

Claims (2)

In the cathode chamber of the electrolytic cell separated by the diaphragm, low-grade larerite is mined with -10 mesh to make a mineral solution with sulfuric acid with a concentration of 0.01-10.0M, and sulfuric acid with a concentration of 0.01-10.0M is placed in the anode chamber. A method of leaching nickel from laterite light that is electrolyzed at negative electrode potential -0.1 to 0.5 volts while blowing. The method according to claim 1, wherein sulfurous acid gas is blown into the cathode chamber to be a saturated solution.