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CN-121992188-A - Method for inhibiting liquid phase generation in fayalite type slag reduction roasting product

CN121992188ACN 121992188 ACN121992188 ACN 121992188ACN-121992188-A

Abstract

The invention provides a method for inhibiting liquid phase generation in a fayalite type slag reduction roasting product, which comprises the steps of mixing fayalite type slag and bentonite for pelletization to obtain slag pellets; and carrying out primary reduction roasting on the obtained slag pellets at 1000-1100 ℃, and continuously heating to 1150-1200 ℃ to carry out secondary reduction roasting. According to the invention, under the condition that additives are not added, the generation of liquid phase in the reduction roasting product of the fayalite type slag can be inhibited by changing the heat history, and the growth of metal iron particles is considered, the process does not generate adhesion and kiln formation, the metallization rate in the reduction roasting product is high, the particle size of the metal iron particles in the obtained reduction roasting product is large, the average size is more than 20 mu m, and the magnetic separation recovery of the subsequent metal iron is more facilitated.

Inventors

  • WANG HONGYANG
  • ZHOU HUILI
  • WANG XIANGYU
  • WU BINGYAN
  • LI ZHAO
  • YANG CHENXI
  • ZHANG XIAOXUE

Assignees

  • 安徽理工大学

Dates

Publication Date
20260508
Application Date
20260121

Claims (9)

  1. 1. A method for suppressing liquid phase formation in a reduced roasting product of fayalite type slag, comprising: mixing fayalite type slag and bentonite for pelletizing to obtain slag pellets; carrying out one-stage reduction roasting on the obtained slag pellets at the temperature of 1000-1100 ℃; And continuously heating to 1150-1200 ℃ for secondary reduction roasting.
  2. 2. The method for suppressing liquid phase formation in a reduced roasting product of fayalite type slag according to claim 1, wherein the iron rugby type slag is one or more of fayalite type slag including copper slag, nickel slag and the like as a main phase.
  3. 3. The method for suppressing liquid phase formation in a reduced roasting product of fayalite type slag according to claim 1, wherein the mass ratio of bentonite to fayalite type slag is 0.5:100 to 5:100.
  4. 4. The method for suppressing liquid phase formation in a reduced roasting product of fayalite type slag according to claim 3, wherein the mass ratio of bentonite to fayalite type slag is 1:100 to 3:100.
  5. 5. The method for suppressing liquid phase formation in a reduced roasting product of fayalite type slag as claimed in claim 1, wherein the duration of the one-stage reduction is not less than 60 minutes.
  6. 6. The method for suppressing liquid phase formation in a reduced roasting product of fayalite type slag according to claim 5, wherein the one-stage reduction period is 60 to 90 minutes.
  7. 7. The method for suppressing liquid phase formation in a reduced roasting product of fayalite type slag according to claim 1, wherein the reducing agent of the primary reduction roasting and the secondary reduction roasting is one or more of CO, coke, coal and charcoal.
  8. 8. The method for suppressing liquid phase formation in a reduced roasting product of fayalite type slag as claimed in claim 1, wherein the duration of the two-stage reduction roasting is 30 to 60 minutes.
  9. 9. The method for suppressing liquid phase formation in a reduced roasting product of fayalite type slag according to claim 1, wherein the primary reduction roasting and the secondary reduction roasting are carried out in a rotary kiln.

Description

Method for inhibiting liquid phase generation in fayalite type slag reduction roasting product Technical Field The invention belongs to the technical field of mineral engineering, and particularly relates to a method for inhibiting liquid phase generation in a reduction roasting product of fayalite type slag. Background At present, the comprehensive utilization rate of fayalite type slag (copper slag, nickel slag and the like) is about 70%, and the yield is increased year by year. Thus, the recycling of fayalite slag has limited the main factor of sustainable development for enterprises. In view of the fact that the iron content in fayalite slag is 30-45%, iron extraction is one of the main research directions for high-value utilization of iron. Patent document with publication number CN106086276a discloses that the process of recovering waste heat by using high-temperature cooling of molten copper slag, adding solvent, heating, and then reducing and roasting again to prepare metallized pellets, which adopts a direct reduction-magnetic separation process, however, the process needs to use a rotary hearth furnace or a shaft furnace with high energy consumption for treatment, and if a rotary kiln with low energy consumption is used, kiln is easy to form, and additional flux is needed to be added; patent document with publication number CN119571050A discloses that copper slag and calcium oxide-based additive are mixed, the modified copper slag is settled to extract iron, the process treatment temperature is high, the energy consumption is high, the requirements on raw material components are severe, and the product is an intermediate product and needs subsequent treatment; the patent document with publication number CN119571049A discloses that copper slag and additives are mixed to obtain mixed copper slag, then self-pulverization is adopted to extract iron, the process treatment temperature is high, the cooling process requires ultra-slow controllable cooling, the required energy consumption is high, excessive additives are additionally added, the patent document with publication number CN111057858A discloses that valuable metals in copper slag secondary alkaline leaching liquid and secondary alkaline leaching slag are recovered, the process requires microwave alkaline leaching, the energy cost is far higher than that of conventional fuel heating, the equipment investment maintenance cost is high, the flow is long, the overall energy efficiency is low, the patent document with publication number CN108676942A discloses that the valuable metals iron, lead and zinc are separated and recovered by blasting, adding coal gangue and other fluxes in a reduction volatilizing furnace, the process treatment temperature is high, the energy requirement of maintaining a high-temperature molten pool, oxygen enrichment and blowing energy consumption and the like, the patent document with publication number CN116043018A discloses that the combined smelting process of iron, lead and zinc are respectively utilized independently and comprehensively at two stages by adopting melting chlorination-reduction iron extraction, the energy consumption is superimposed, so that the total energy consumption is high, in addition, the efficiency of the equipment is fast reduced in a corrosive high-temperature environment, the maintenance period is short, and the long-term operation energy efficiency is difficult to maintain. Disclosure of Invention The present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a method for suppressing the generation of a liquid phase in a reduced roasting product of fayalite-type slag, which can suppress the generation of a liquid phase in a reduced roasting product of fayalite-type slag by thermal history without adding an additive and which gives consideration to the growth of metallic iron particles, thereby creating advantageous conditions for the subsequent recovery of metallic iron by magnetic separation. In order to achieve the above purpose, the invention adopts the following technical scheme: a method for inhibiting liquid phase formation in a reduced roasting product of fayalite type slag, comprising: mixing fayalite type slag and bentonite for pelletizing to obtain slag pellets; carrying out one-stage reduction roasting on the obtained slag pellets at the temperature of 1000-1100 ℃; And continuously heating to 1150-1200 ℃ for secondary reduction roasting. Further, the fayalite-type slag in the step (1) includes one or more of fayalite-type slag in which a main phase such as copper slag and nickel slag is fayalite-type slag. Further, the mass ratio of the bentonite to the fayalite type slag is 0.5:100-5:100. Further, the mass ratio of the bentonite to the fayalite type slag is 1:100-3:100. Further, the duration of the one-stage reduction is not less than 60 minutes. Further, the period of time for the one-sta