EN
Determination of copper content in ore
When analyzing non-ferrous metal ores and their enrichment products, the following are determined first:
- The main metals contained in the ore.
- Rock components (slag-forming components).
- Alkali metals.
- Sulfur, and sometimes other metalloids.
Copper, like other components in ore, is determined by a wide range of methods, determined by both the chemical and physical properties of the elements. Each method has its own merits and is selected based on key aspects of the nature of the ore, sample, further processing of both the ore and the data obtained.
Chemical methods are based on the use of chemical reaction intensities and other chemical parameters characteristic of each element to accurately determine concentrations. However, these methods are very long-term and labor-intensive, which does not allow for prompt information (without large time delays). But this does not mean that these methods will eventually sink into oblivion, because subsequent faster methods will displace them from the "industrial and scientific arena". This is primarily due to the fact that faster methods are mainly based on data obtained by more accurate and labor-intensive methods, being, to some extent, descendants of these technologies.
Let us consider a number of typical methods for extracting copper from ore.
1) Separation of copper with sodium thiosulfate. This reaction proceeds according to the scheme
2Cu 2 + + 2S 2 O 3 2- ->Cu 2 S + 3SO 2
Metals of III and II analytical groups are not precipitated by sodium thiosulfate in an acidic medium.
2) Release of copper by hydrogen sulfide
Cu2 + + CdS=CuS + Cd2 +
This reaction proceeds quantitatively from left to right.
3) The extraction of copper with sodium sulfide is used to separate copper (as well as lead, cadmium, mercury, silver) from metals of the V analytical group (arsenic, antimony and tin), which form sulfosalts with sodium sulfide.
4) The iodometric method is very common in industrial laboratories, which gives the same accurate results as the electrolytic method. This method is based on the reaction of the reduction of divalent copper to its monovalent form by potassium iodide.
2Cu 2+ + 4J <- -> Cu 2 J 2 + J 2
Physical methods are based on the excitation of the surface layers of the ore by various types of radiation, namely: X-ray, optical, laser, neutron, etc., and physical methods also include various magnetic and electrolytic methods.
Among radiometric methods , the most common devices are those based on the use of X-ray tubes and sources. These devices excite the atoms of elements in the ore, which in turn remove their excitation by emitting characteristic X-rays. The detector registers the characteristic rays, obtaining a spectrum similar to the spectrum shown in Fig. 1.
The process of obtaining this spectrum requires studying additional literature, but in almost all detectors it is implemented automatically. Next, the intensities of excited elements are calculated, and calibration is performed according to the initially specified parameters obtained by more accurate methods!!!. In the first approximation, the concentration of elements in the ore is proportional to K i I i , where I i is the intensity of the element, for example Cu (E = 8.02 keV), K i is the calibration coefficient. The resulting calibration is then used at enterprises as a quick and express analysis of ore coming from the mine.
This method is complete and universal, which served as the basis for the creation of the ARP-1C flow analyzer of ore and pulp, which allows determining the content of elements from Ca to U, in the concentration range from 0.05% to 90%.
