Method for treating semi-autogenous grinding hard rock through heap leaching of low-copper raffinate

Abstract

The invention relates to a method for treating semi-autogenous grinding hard rock through dump leaching of low-copper raffinate, and solves the problems of power consumption increase, treatment capacity reduction and cost increase caused by the fact that returned hard rock occupies part of the treatment capacity of a semi-autogenous grinding machine in an existing method. The method comprises the following steps: 1) crushing the copper oxide cobalt ore, grinding the crushed copper oxide cobalt ore in a semi-autogenous mill, leaching screen underflow for H2SO4 acid leaching, and extracting a low-copper solution generated after CCD (Charge Coupled Device) washing after leaching to generate low-copper raffinate; (2) the hard rock is transferred to a dump leaching site to be stacked, then low-copper raffinate is used for conducting spraying leaching on the hard rock, and copper-cobalt leaching liquid obtained after leaching is mixed with the low-copper raffinate to conduct repeated spraying leaching on the hard rock heap; 3, a part of the low-copper raffinate enters a thickener to remove iron, a part of the low-copper raffinate is mixed with dump leaching liquid, and hard rock dump leaching is performed with spraying leached, and 4, a part of the hard rock leaching liquid enters the thickener to remove iron, a part of the hard rock leaching liquid is mixed with the low-copper raffinate, and hard rock dump leaching is performed with spraying leached.

Description

Technical Field

[0001] This invention relates to the field of mineral processing and copper-cobalt hydrometallurgical technology, specifically to a method for treating semi-autogenous ore using low-copper raffinate heap leaching. Background Technology

[0002] In existing processes for processing conventional copper-cobalt oxide ores, the ore undergoes coarse crushing, then is conveyed to an autogenous mill for grinding. The resulting slurry passes through a cylindrical screen, with the undersize material entering the next leaching system for H2SO4 acid leaching. The oversize material consists of "hard-to-grind particles," or stubborn stones, generated during the autogenous mill's operation. Current processes often employ either a coarse crushing + semi-autogenous mill + ball mill + stubborn stone crushing (SABC) process or a coarse crushing + semi-autogenous mill + ball mill (ABC) process. In both processes, stubborn stones must be returned to the semi-autogenous mill. This returned stone inevitably reduces the semi-autogenous mill's processing capacity, leading to increased power consumption, decreased throughput, and higher costs. Summary of the Invention

[0003] This invention proposes a new process flow method in which the ore produced in the semi-autogenous grinding mill is not returned to the semi-autogenous grinding mill, but is directly transferred to the heap leaching site for heap leaching. The ore is then sprayed with low-copper raffinate to consume the residual acid in the low-copper raffinate, thereby reducing the cost of neutralizing residual acid during the cobalt precipitation process. At the same time, the valuable copper and cobalt metals in the ore are recovered.

[0004] This invention is achieved through the following technical solutions: A method for treating semi-autogenous grinding rocks using low-copper raffinate heap leaching includes the following steps: 1) After being crushed, the copper-cobalt oxide ore is ground in a semi-autogenous mill. The qualified slurry enters the rear cylindrical screen for screening. The undersize material enters the leaching process for H2SO4 acid leaching. After leaching, it is washed by a CCD. The low-copper solution produced after washing enters the extraction process to produce low-copper raffinate. 2) The oversize material (dead rocks) is transferred to the heap leaching site via conveyor belt or other transport vehicles; 3) The sieved pebbles are piled up in the heap leaching site, and then sprayed with the low copper raffinate obtained in step 1). The copper and cobalt leaching solution is collected in the solution tank. This solution is mixed with the low copper raffinate and repeatedly sprayed to leach the pebbles to increase the copper and cobalt content. 4) A portion of the low-copper leaching residue is sent to a thickener for iron removal, and another portion is mixed with the heap leaching liquid for spray leaching of the sturdy rock heap. 5) Part of the leachate from the stubborn rock is sent to a thickener to remove iron, and part is mixed with the low-copper raffinate to perform spray leaching on the stubborn rock pile. 6) After iron removal, the slurry enters the copper thickener. The slurry from the copper thickener enters the leaching process to recover copper. The overflow from the copper thickener enters the cobalt precipitation workshop.

[0005] The semi-self-abrasive stone has a particle size between 10mm and 60mm.

[0006] The beneficial effects of this invention are: (1) Compared with the coarse crushing + semi-autogenous grinding + ball milling + sabc process, the combined process of sabc process can reduce the energy consumption of semi-autogenous grinding, reduce the consumption of steel balls in semi-autogenous grinding, and increase the throughput. (2) The process of heap leaching of boulders is simple, easy to operate, and low in cost; (3) Recover valuable metals from stubborn rocks to increase economic benefits; (4) There is no mud or sand in the stubborn rock. The stubborn rock pile has strong permeability, which can improve the leaching rate and the quality of the leaching liquid. (5) The permeability of the rock is high, which can reduce acid consumption and shorten the leaching cycle; (6) Copper-cobalt leaching is achieved by using residual acid in low copper raffinate (H2SO4 5–15 g / L).

[0007] (7) Reduce the cost of neutralizing substances during cobalt precipitation and increase economic benefits. Attached Figure Description

[0008] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0009] like Figure 1 As shown, this invention proposes a new combined process flow, in which the ore is not returned to the semi-autogenous grinding process or subjected to waste disposal, but directly enters the heap leaching system for heap leaching. It is sprayed with low copper leaching residue to consume the residual acid in the low copper leaching residue, reduce the cost of neutralizing substances in the cobalt precipitation process, and recover valuable copper and cobalt metals from the ore.

[0010] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0011] Example: In an African copper-cobalt oxide mine, the slag discharged from the mill was directly subjected to heap leaching. The residual acid (H2SO4, 5–20 g / L) in the copper extraction residue was used for spraying, resulting in a copper leaching rate of over 65% and a cobalt leaching rate of over 50%.

Claims

1. A method for treating semi-autogenous grinding rocks using low-copper raffinate heap leaching, characterized in that: Includes the following steps: 1) After being crushed, the copper-cobalt oxide ore is ground in a semi-autogenous mill. The qualified slurry enters the rear cylindrical screen for screening. The undersize material enters the leaching process for H2SO4 acid leaching. After leaching, it is washed by a CCD. The low-copper solution produced after washing enters the extraction process to produce low-copper raffinate. 2) The slag oversize material is transferred to the heap leaching site; 3) The sieved pebbles are piled up in the heap leaching site, and then sprayed with the low copper raffinate obtained in step 1). The copper and cobalt leaching solution is collected in the solution tank. This solution is mixed with the low copper raffinate and repeatedly sprayed to leach the pebbles to increase the copper and cobalt content. 4) A portion of the low-copper leaching residue is sent to a thickener for iron removal, and another portion is mixed with the heap leaching liquid for spray leaching of the sturdy rock heap. 5) Part of the leachate from the stubborn rock is sent to a thickener to remove iron, and part is mixed with the low-copper raffinate to perform spray leaching on the stubborn rock pile. 6) After iron removal, the slurry enters the copper thickener. The slurry from the copper thickener enters the leaching process to recover copper. The overflow from the copper thickener enters the cobalt precipitation workshop.

2. The method for treating semi-autogenous grinding rocks using low-copper raffinate heap leaching according to claim 1, characterized in that: The semi-self-abrasive stone has a particle size between 10mm and 60mm.

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