Search

CN-121976056-A - Method for improving selectivity of copper smelting slag

CN121976056ACN 121976056 ACN121976056 ACN 121976056ACN-121976056-A

Abstract

The invention provides a method for improving the selectivity of copper smelting slag, which comprises the following steps of controlling the addition amount of a solvent according to raw material components entering a furnace, controlling the oxygen partial pressure and the smelting temperature in the smelting process, reducing and depleting atmosphere and reducing and depleting temperature to obtain molten slag, and cooling the molten slag after casting, wherein the mass ratio of Fe to SiO 2 in the molten slag is 1.3-1.8, the mass content of Fe 3 O 4 is less than or equal to 10%, the mass content of Al 2 O 3 is less than or equal to 4%, and the S/Cu molar ratio is more than or equal to 0.3. According to the method, the smelting reaction conditions are precisely controlled, the key properties of the slag are optimized from the source, and the cooling mode is matched for the slag with specific properties, so that the selectivity of copper minerals is fundamentally improved.

Inventors

  • YANG CAIWEN
  • KONG LINGXIN
  • YANG BIN
  • FANG HAOYU
  • DONG CHAOWANG

Assignees

  • 昆明理工大学

Dates

Publication Date
20260505
Application Date
20251226

Claims (9)

  1. 1. A method for improving the selectivity of copper smelting slag, comprising the steps of: Controlling the addition amount of the solvent according to the raw material components fed into the furnace; controlling the oxygen partial pressure and the smelting temperature in the smelting process, and reducing and depleting atmosphere and reducing and depleting temperature to obtain molten slag; The molten slag is cooled after casting, wherein, The mass ratio of Fe to SiO 2 in the molten slag is 1.3-1.8, the mass content of Fe 3 O 4 is less than or equal to 10%, the mass content of Al 2 O 3 is less than or equal to 4%, and the S/Cu molar ratio is more than or equal to 0.3.
  2. 2. The method for improving the selectivity of copper smelting slag according to claim 1, wherein the oxygen partial pressure in the smelting process is 10 -8 ~10 -10 MPa and the smelting temperature is 1150-1250 ℃.
  3. 3. The method for improving the selectivity of copper smelting slag according to claim 1 or 2, wherein the reduction and depletion atmosphere is 0.5-2.0 in the volume ratio of CO/CO 2 , and the reduction and depletion temperature is 1200-1250 ℃.
  4. 4. The method of increasing the selectivity of copper smelting slag according to claim 1 or 2, wherein the post-casting cooling of the molten slag comprises: Slowly cooling the molten slag to 700-800 ℃ after casting; Naturally cooling in air to final cooling temperature after slow cooling is finished; the final cooling temperature is controlled to be lower than 40 ℃.
  5. 5. The method for improving the selectivity of copper smelting slag according to claim 4, wherein the slow cooling time is controlled to be more than 10 hours, the natural cooling time in air is controlled to be more than 15 hours, and the cooling time to the final cooling temperature is controlled to be more than 75 hours.
  6. 6. The method for improving the selectivity of copper smelting slag according to claim 5, wherein the slow cooling time is controlled to be 10-15 hours, the natural cooling time in air is controlled to be 15-20 hours, and the cooling time to the final cooling temperature is controlled to be 75-100 hours.
  7. 7. The method for improving the selectivity of copper smelting slag according to claim 1, 2, 5 or 6, wherein the S/Cu molar ratio is 0.35 to 0.55.
  8. 8. The method for improving the selectivity of copper smelting slag according to claim 1,2, 5 or 6, wherein the content of Fe 3 O 4 is 8% or less by mass.
  9. 9. The method for improving the selectivity of copper smelting slag according to claim 1,2, 5 or 6, wherein the content of Al 2 O 3 is not more than 3.5% by mass.

Description

Method for improving selectivity of copper smelting slag Technical Field The invention relates to the field of nonferrous metal smelting, in particular to a method for improving the selectivity of copper smelting slag. Background Valuable metals such as copper are rich in copper smelting slag and are usually recovered through a beneficiation process. However, the recovery efficiency of copper is closely related to the occurrence of copper in slag, including grain size, mineral type, and intercalation characteristics. These conditions are fundamentally affected by the combination of the control of the smelting reaction, the physicochemical properties of the slag and the cooling process. Currently, the industry has noted the impact of slag composition on beneficiation indicators and attempted to improve slag properties by adjusting smelting process parameters. However, existing studies have had a lack of inherent correlation between the systematic disclosure of "reaction conditions-slag composition-slag properties-options" and failed to achieve precise synergy of source reaction control, property regulation and cooling regimes. Although the slow cooling technology widely adopted at present can partially promote mineral crystallization, if slag components and structures are deteriorated due to improper smelting control or a cooling system is unreasonable in design, the problems of insufficient copper mineral crystallization, too fine grains, red heart slag even and the like are still easily caused, and the subsequent ore grinding-flotation effect is seriously influenced. Therefore, there is an urgent need to establish a system method for precisely regulating and controlling the key properties of slag from a smelting source and matching an optimal cooling system based on different slag characteristics, so as to fundamentally improve the occurrence state and the selectivity of copper minerals and improve the resource recovery efficiency. Disclosure of Invention An object of the present invention is to solve one or more of the problems occurring in the prior art, in view of the disadvantages of the prior art. For example, it is an object of the present invention to provide a method for optimizing copper mineral crystallization behavior and occurrence and improving copper smelting slag selectivity. The invention provides a method for improving the selectivity of copper smelting slag, which comprises the following steps of controlling the addition amount of a solvent according to raw material components entering a furnace, controlling the oxygen partial pressure and the smelting temperature in the smelting process, reducing and depleting atmosphere and reducing and depleting temperature to obtain molten slag, and cooling the molten slag after casting, wherein the mass ratio of Fe to SiO 2 in the molten slag is 1.3-1.8, the mass content of Fe 3O4 is less than or equal to 10%, the mass content of Al 2O3 is less than or equal to 4%, and the S/Cu molar ratio is more than or equal to 0.3. Further, the oxygen partial pressure in the smelting process can be 10 -8~10-10 MPa, and the smelting temperature can be 1150-1250 ℃. Further, the reduction and dilution atmosphere can be CO/CO 2 volume ratio of 0.5-2.0, and the reduction and dilution temperature can be 1200-1250 ℃. Further, the cooling after the casting of the molten slag can comprise slowly cooling the molten slag to 700-800 ℃ after the casting, naturally cooling in air to a final cooling temperature after the slow cooling is finished, and controlling the final cooling temperature to be lower than 40 ℃. Further, the slow cooling time can be controlled to be more than 10 hours, the natural cooling time in the air can be controlled to be more than 15 hours, and the cooling time to the final cooling temperature can be controlled to be more than 75 hours. Further, the slow cooling time can be controlled to be 10-15 hours, the natural cooling time in the air can be controlled to be 15-20 hours, and the cooling time to the final cooling temperature can be controlled to be 75-100 hours. Further, the S/Cu molar ratio may be 0.35 to 0.55. Further, the mass content of Fe 3O4 can be less than or equal to 8%. Further, the mass content of Al 2O3 can be less than or equal to 3.5%. Compared with the prior art, the invention has the beneficial effects that at least one of the following components is contained: (1) The method of the invention actively shapes an ideal smelting reaction path by means of the cooperative regulation and control of smelting key parameters and the precise control of oxygen potential, temperature and ingredient composition, builds a solid starting point for the subsequent links, and ensures that slag has excellent chemical components and physical property basis from the source. (2) The method takes the oriented optimization of the physical and chemical properties of the slag as a core, creates superior conditions for the efficient crystallization of copper m