JPS61127832A - Elution of silver and other valuables contained in ore - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for leaching silver and other valuable metals contained in ore, and in particular to a method for leaching silver and other valuable metals contained in ore without being affected by the sulfur content in ore. The present invention relates to a leaching method that allows components to be leached.

The present invention can also be applied to the in-place leaching method and the heap leaching method.

BACKGROUND OF THE INVENTION Leaching operations, in which valuable metals in ores or concentrates are eluted with a suitable solvent, leaving impurities and gangue that are poorly soluble in the solvent, have long been known as a useful method of hydrometallurgical smelting technology. It is being When leaching metals such as gold and silver, the assimilation method, which involves leaching with a dilute NaCN solution, is generally used, but if the assimilation method is applied when a large amount of sulfide is present in the ore, 1,000 osyanide ions (-CNS) in the liquid
is generated, leading to increased consumption of leaching agent and decreased metal leaching rate. Therefore, it is common to apply a backing method in which desulfurization treatment is performed in advance by flotation, selective selection, roasting, etc. However, even if the assimilation method is applicable as a process, it is extremely difficult to actually implement the assimilation method under the current circumstances where it is difficult to obtain sanitation from the environment surrounding the use of cyanide.

In addition, leaching methods using acids or alkalis are known for leaching copper 1, uranium, etc., but they lack the ability to leach gold and silver, so they have not been applied to magnets made of various metal minerals containing gold and silver. There is no.

On the other hand, chlorine has been known for a long time as a leaching agent for gold and silver that is as good as cyanide, but it is rarely used today because it is highly corrosive to metals.

Therefore, it is desired to establish a leaching method for recovering gold and silver from ores without using assimilation methods.

The present invention is particularly directed to the development of a leaching process for recovering silver from ores with concomitant other valuable metals.

Summary of the Invention The present inventor focused on the leachability of chlorine to various metals,
We have repeatedly investigated leaching methods that effectively utilize the leachability of chlorine while avoiding its corrosive properties. As a result, it was found that the combined use of common salt and a chlorine-based reagent is suitable for the above purpose. In the present invention, the crude ore can be directly leached, but it is more effective if the crude ore is leached after being roasted. Furthermore, if acid leaching is performed prior to leaching with common salt and a chlorine-based reagent, acid-leaching zinc and the like can be recovered quickly, which is even more convenient.

Thus, the present invention provides a leaching method characterized by using a combination of common salt and a chlorine-based reagent as a leaching agent when leaching silver and other valuable metals from crude ore. A preferred chlorinated reagent is sodium hypochlorite.

DETAILED DESCRIPTION OF THE INVENTION The present invention is not only useful for leaching crushed raw ore in leaching equipment, but also for in-place leaching, in which cracks are created artificially in the donated body itself and the leachate is poured from the top of the pile. It can also be suitably applied to heap leaching, which involves piling up ore and pouring leachate over the top to perform leaching. Therefore, it can also be used as a leaching method to economically and efficiently recover valuable metals from low-grade ores and difficult-to-mine ores. Useful. Here, the leaching treatment of crushed ore will be explained.

The raw ore is ground to a size suitable for leaching operations, such as -10 mesh. The ore grains can be leached as they are using a leaching facility, but it is more effective if they are roasted beforehand and then leached, and more valuable metals in the form of sulfides can be leached out. Furthermore, prior to the salt + chlorine reagent leaching according to the present method, a separate pre-leaching operation is performed to selectively recover certain metal species at an early stage, depending on the type and content of valuable metals contained in the ore. It's okay.

For example, acid leaching such as sulfuric acid leaching, nitric acid leaching, or alkaline leaching such as ammonia leaching may be performed.

Thus, the ore grains, with or without optional roasting and/or preleaching, are subjected to the leaching process of the present invention in order to leach the silver contained therein along with other valuable metals. As the leaching tank, any conventional osmotic leaching tank, stirring leaching tank, autoclave, etc. can be used.

The leaching agent is a combination of common salt and a chlorinated reagent.

Examples of chlorine-based reagents include hypochlorites such as sodium hypochlorite and potassium hypochlorite, and chlorite (13)
Typically, chlorites such as um and chloracetates such as sodium chlorate are used, but sodium hypochlorite is preferred. Generally, salt is used in a composition range of 25 to b. If the amount of the chlorine-based reagent is less than 5%, the leaching effect will be poor, while if it is added in an amount of 20% or more, the effect will remain the same, but the cost will increase. In addition, it is also possible to blow in chlorine gas by bubbling or the like.

The liquid temperature is at least room temperature, preferably 60 to 95°C.

After leaching for a suitable period of time, solid-liquid separation is carried out by filtration or the like, and the leaching solution from which silver and other valuable metals have been leached is recovered.

Example 1 Au A conducted a trial t in which raw ore having the following raw ore grade was leached with direct acid and brine with sodium hypochlorite.
g Cm Pb Zn Fe S test was conducted under the conditions shown in the following system diagram.

The leaching results are shown in the table below.

Ag Zn Pb Acid leaching <3% 5% Insoluble (saline water, NaCl0) leaching 100% 4.4%
43% silver is 100% leached, along with a large amount of PB
It can be seen that a small amount of Zn was leached out.

Example 2 A similar test was conducted on crude ore produced from a different mine than in Example 1, this time incorporating a roasting process. The raw ore grades are as follows: An Ag Co Pb Z
n F@Sα511/l 14011
/l α22% 12.84% 25. ．． 45% 8
．． 07% 2175% The test conditions were as follows: The leaching results were as follows, and as in Example 1, A
00% recovered. By incorporating the roasting process, Zn
could be recovered early by acid leaching.

Ag Zn Pb Acid leaching <α3% 80% Insoluble (saline water molecule NaCl0) leaching 100% 6%
147% Effect of the invention Since the silver contained in crude ore can be effectively recovered together with other valuable metals and the problem of corrosivity of chlorine is avoided, this method will contribute to the industry as a leaching method in place of the back ratio method. Seem.

Claims (1)

[Claims] 1) When leaching silver and other valuable metals from crude ore,
A leaching method characterized by using a combination of common salt and a chlorine-based reagent as a leaching agent. 2) The leaching method according to claim 1, in which sodium hypochlorite is used as the chlorine-based reagent.