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CN-121270223-B - High-strength nano polycrystalline gunning material for nonferrous metal smelting furnace and preparation method thereof

CN121270223BCN 121270223 BCN121270223 BCN 121270223BCN-121270223-B

Abstract

The invention belongs to the technical field of refractory materials, and relates to a high-strength nano polycrystalline gunning material for nonferrous metal smelting furnaces and a preparation method thereof. The high-strength nano polycrystalline gunning material comprises, by weight, 30-45 parts of high-purity fused magnesia, 15-20 parts of fused magnesia chrome sand, 5-7 parts of fused chrome corundum, 10-20 parts of polycrystalline nano magnesia, 3-5 parts of CA-80 calcium aluminate cement, 3-5 parts of silica sol, 8-15 parts of chromium oxide micro powder and 2-3 parts of sodium carboxymethyl cellulose. After the copper smelting anode furnace (Kaldo furnace) is sprayed, the erosion resistance and the thermal shock stability are improved, and the service life is prolonged.

Inventors

  • ZHANG HAIFENG
  • OuYang Benhui
  • CHU DECHENG
  • YU GUOQIANG

Assignees

  • 辽宁铜耐科技有限公司
  • 辽宁中镁高温材料有限公司

Dates

Publication Date
20260505
Application Date
20251105

Claims (10)

  1. 1. The high-strength nano polycrystalline gunning material for the nonferrous metal smelting furnace is characterized by comprising the following raw materials, by weight, 30-45 parts of high-purity fused magnesia, 15-20 parts of fused magnesia-chrome sand, 5-7 parts of fused chrome corundum, 10-20 parts of polycrystalline nano magnesia, 3-5 parts of CA-80 type calcium aluminate cement, 3-5 parts of silica sol, 8-15 parts of chromium oxide micro powder and 2-3 parts of sodium carboxymethyl cellulose.
  2. 2. The high-strength nano polycrystalline gunning material for nonferrous metal smelting furnace according to claim 1, wherein the main components of the high-purity fused magnesia are MgO not less than 97%, caO not more than 1.0%, siO 2 ≤0.8,Fe 2 O 3 not more than 0.5%, loss on ignition not more than 0.5% and the granularity is 3-5mm.
  3. 3. The high-strength nano polycrystalline gunning material for nonferrous metal smelting furnace according to claim 1, wherein the main components of the electric smelting magnesia chrome sand are MgO not less than 65%, cr 2 O 3 20%-25%、Al 2 O 3 ≤3%、Fe 2 O 3 not more than 2% and the granularity is 0-3mm.
  4. 4. The high-strength nano polycrystalline gunning material for nonferrous metal smelting furnace according to claim 1, wherein the granularity of the main component Cr 2 O 3 ≥25%、Al 2 O 3 ≥70%,SiO 2 ≤1.0%,Fe 2 O 3 ≤0.5%,TiO 2 ≤0.3%, is less than or equal to 0.074mm.
  5. 5. The high-strength nano polycrystalline gunning material for nonferrous metal smelting furnace according to claim 1, wherein the main index of the polycrystalline nano magnesia is that the grain diameter is 10-50nm, the specific surface area is 80-120m2/g, the purity is more than or equal to 99.5%, the impurity Fe 2 O 3 ≤0.05%、CaO≤0.1%、SiO 2 is less than or equal to 0.1%, the grain size in the crystal structure is less than or equal to 30nm, and the grain boundary content accounts for 15% -20%.
  6. 6. The high-strength nano polycrystalline gunning material for nonferrous metal smelting furnace according to claim 1, wherein the main component of the CA-80 type calcium aluminate cement is Al 2 O 3 ≥80%、CaO≤18%,SiO 2 ≤0.5%,Fe 2 O 3 which is less than or equal to 0.5%, the initial setting time is more than or equal to 45min, the final setting time is less than or equal to 120min, and the granularity is 0.045mm.
  7. 7. The high-strength nano-polycrystalline gunning material for nonferrous metal smelting furnace according to claim 1, wherein the main component of the chromium oxide micro powder is Cr 2 O 3 ≥98%、Fe 2 O 3 ≤0.3%,SiO 2 -0.5%, caO-0.2% and granularity-0.045 mm.
  8. 8. The preparation method of the high-strength nano polycrystalline gunning material for the nonferrous metal smelting furnace is characterized by comprising the following steps of: firstly, premixing polycrystalline nano magnesium oxide, chromium oxide micro powder, electro-fused chrome corundum and CA-80 type calcium aluminate cement to obtain a premix; Step 2, mixing materials by adopting a sand mixer, wherein the mixing sequence is that firstly, granule materials, namely high-purity electric smelting magnesia and electric smelting magnesia-chrome sand are added, mixed and stirred, and then premix materials are added and stirred, so as to obtain a mixture; And 3, preparing gunning slurry, namely adding the mixture in the step 3 into silica sol, clean water and sodium carboxymethyl cellulose, mixing and stirring, and controlling the water content and viscosity of the slurry to obtain the high-strength nano polycrystalline gunning material for the nonferrous metal smelting furnace.
  9. 9. The method for preparing high-strength nano-polycrystalline gunning material for nonferrous metal smelting furnace according to claim 8, wherein the mixing time in step 1 or step 3 is 10-15 minutes.
  10. 10. The method for preparing high-strength nano polycrystalline gunning material for nonferrous metal smelting furnace according to claim 8, wherein in the step 3, the water content of slurry is 18% -22%, and the viscosity is 500-800 mpa.s at 25 ℃.

Description

High-strength nano polycrystalline gunning material for nonferrous metal smelting furnace and preparation method thereof Technical Field The invention belongs to the technical field of refractory materials, and particularly relates to a high-strength nano polycrystalline gunning material for a nonferrous metal smelting furnace and a preparation method thereof. The gunning mix is especially aimed at the easily eroded parts such as a molten pool, a furnace door, a furnace mouth and the like of a crude copper refining furnace such as an anode furnace (a Kaldo furnace). Background In the nonferrous metal smelting field (such as an anode furnace for refining blister copper, such as a Kaldo furnace), the magnesia-chrome brick serving as a main lining material is excellent in high temperature resistance (capable of tolerating high temperature of 1100-1350 ℃ copper liquid) and copper slag corrosion resistance, and is used as a lining refractory material for core parts of a kiln molten pool, a furnace door, a furnace mouth and the like for a long time, the performance of the magnesia-chrome brick directly determines the operation stability and production continuity of the smelting furnace, and the magnesia-chrome brick is a core basic component for guaranteeing the efficient promotion of the blister copper refining process. However, the magnesia-chrome brick needs to continuously bear the superposition of multiple severe working conditions in the long-term service process, on one hand, the high-speed scouring of high-temperature copper liquid at 1100-1350 ℃ can continuously abrade the surface of the brick body, iron oxide, silicon dioxide and other components in slag can also chemically react with the magnesia-chrome brick to generate a low-melting-point phase, so that the brick body is chemically eroded, on the other hand, the temperature difference of the smelting furnace can reach hundreds of ℃, the cold and hot temperature suddenly changes caused by the operation of starting and stopping the smelting furnace and discharging copper, the thermal stress is easily generated in the brick body, the damage such as spalling, cracking and erosion pits is caused, and meanwhile, the copper liquid permeates into the pores of the brick body and then is cooled and expanded, so that the structural damage is further aggravated. In order to avoid safety accidents such as kiln leakage and structural failure caused by damage expansion, the damaged part needs to be repaired in time, the repair operation is often carried out along with the shutdown of a smelting furnace, namely, the current refining flow is interrupted, the process needs 8-16 hours when the furnace temperature is reduced to below 300 ℃, workers can enter the furnace or repair can be carried out by special equipment, the temperature needs to be increased to the temperature required by production again after the repair is completed, the whole process takes time and is long, and synchronous production cannot be carried out. The frequent repair and furnace shutdown caused by the damage of the magnesium-chromium bricks become key bottlenecks for restricting the smelting efficiency of nonferrous metals, the production efficiency is seriously reduced by reducing the yield of blister copper by 15% -25% in unit time, the production cost is greatly increased by generally 8-20 ten thousand yuan in the process of furnace shutdown, more importantly, the frequent cold-hot circulation can accelerate the ageing of the magnesium-chromium bricks and the metal shells of the smelting furnaces, the service life of the magnesium-chromium bricks is shortened to 2-3 months from 3-4 months, the integral maintenance period of the furnace body is advanced, the equipment replacement cost is increased by 25% -40%, the reheating after each furnace shutdown is carried out is required to consume a large amount of fuel, the energy consumption for single heating is equivalent to the total energy consumption for 2-4 days of normal production, the energy consumption for each year is 10% -18% of the total energy consumption for the furnace shutdown, the energy waste and the environmental protection pressure are greatly increased, the frequent furnace shutdown and the heating can lead to unstable internal temperature fields and flow fields of the smelting furnaces, for example, the furnace temperature fluctuation can cause uneven copper components in the course in the crude copper refining process, the copper liquid is removed, the final copper content is not uniform, the copper content is reduced by 99.99% and the quality of the product is greatly reduced, the product quality is greatly reduced, and the quality is greatly influenced by the quality and has the quality is greatly improved. The gunning mix is widely used as a common repairing means for ladle and electric furnace, and has good effect for maintaining the furnace lining of the converter. In recent years, gunning materials have been used as a