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CN-118063236-B - Foamed ceramic prepared from calcium-rich magnesium-molybdenum tailings and preparation method thereof

CN118063236BCN 118063236 BCN118063236 BCN 118063236BCN-118063236-B

Abstract

The invention discloses a foamed ceramic prepared from calcium-rich magnesium-molybdenum tailings and a preparation method thereof, wherein the raw materials comprise, by mass, 50-70% of molybdenum tailings, 15-25% of fly ash, 10-25% of kaolin, 5-15% of silicon tailings and 2-8% of alumina, the mass of the foaming agent is 0.4-1.0% of the mass of the base material, the foamed ceramic provided by the invention is based on a Si-Al-Mg-Ca component system, the high utilization rate of the molybdenum tailings is realized, other solid waste materials in the area are fully utilized, the utilization rate of the solid waste materials in the foamed ceramic is further improved, the utilization rate of the molybdenum tailings is not lower than 50%, the total solid waste material is not lower than 70%, and the foamed ceramic has a uniform and dense pore structure.

Inventors

  • SHI QING
  • ZHANG XIANGMING
  • Tu Quanping
  • MENG FANWEI
  • ZHANG FENG
  • ZHANG GUOFAN

Assignees

  • 中南大学
  • 河北矿业资源有限责任公司

Dates

Publication Date
20260505
Application Date
20240129

Claims (4)

  1. 1. The preparation method of the foamed ceramic prepared by using the calcium-rich magnesium-molybdenum tailings is characterized by comprising the steps of preparing a base material and a foaming agent according to a designed proportion, performing wet ball milling and drying on the base material and the foaming agent to obtain a mixture, crushing the mixture to obtain powder, forming the powder to obtain a blank, and sintering the blank to obtain the foamed ceramic; The sintering process comprises heating to 850-950 deg.C at 8-12 deg.C/min, heating to 1100-1150 deg.C at 3-6 deg.C/min, and maintaining for 20-40min; The foaming ceramic comprises, by mass, 50-60% of molybdenum tailings, 15-25% of fly ash, 12-25% of kaolin, 5-15% of silicon tailings and 2-3% of aluminum oxide, wherein the mass of the foaming agent is 0.4-1.0% of the mass of the base material, and the main chemical composition of the molybdenum tailings is as follows ：SiO 2 48-55%,MgO 12-18%,CaO 8-13%,Al 2 O 3 5-10%,Fe 2 O 3 4-8%,K 2 O 3-6%.
  2. 2. The method for preparing foamed ceramic by using calcium-rich magnesium-molybdenum tailings according to claim 1, wherein the base material and the foaming agent are dried at 40-60 ℃; In the wet ball milling process, the ball milling medium is water, wherein the mass ratio of the base material to the foaming agent to the water is 1:1-1.2, and the wet ball milling time is 20-30min.
  3. 3. The method for preparing foamed ceramic by using calcium-rich magnesium-molybdenum tailings according to claim 1, wherein the forming mode is stack forming or dry pressing forming; The pile is formed by uniformly paving powder to fill the mould and compacting; the dry pressing is carried out by spraying 6-8% water or polyethylene glycol into the powder, aging for 16-24h, and then transferring into a mould for pressing.
  4. 4. The method for preparing foamed ceramic by using calcium-rich magnesium-molybdenum tailings according to any one of claims 1 to 3, wherein the particle size of the molybdenum tailings is less than or equal to 74 μm; the kaolin comprises, by mass, siO 2 48-52%,Al 2 O 3 , 44-48%; The granularity of the kaolin is less than or equal to 74 mu m; The fly ash comprises, by mass, 1-6% of SiO 2 35-45%,Al 2 O 3 27-40%,CaO 1-5%,Fe 2 O 3 and 0-3% of MgO; The granularity of the fly ash is less than or equal to 74 mu m; The silicon tailings comprise, by mass, 2-5% of SiO 2 80-85%,Al 2 O 3 and 1-3% of CaO; The granularity of the silicon tailings is less than or equal to 74 mu m; the foaming agent is industrial silicon carbide, and the granularity of the foaming agent is less than or equal to 10 mu m.

Description

Foamed ceramic prepared from calcium-rich magnesium-molybdenum tailings and preparation method thereof Technical Field The invention relates to foamed ceramic prepared from calcium-rich magnesium-molybdenum tailings and a preparation method thereof, and belongs to the technical field of comprehensive utilization of industrial wastes. Background The molybdenum ore is subjected to a flotation process, tailings with the total amount of more than 95% of the ore are produced, and the tailings are stored for a long time, so that the tailings not only occupy the land, but also have environmental hazard. The foamed ceramic material with the performances of light weight, high strength, heat preservation, heat insulation, fire resistance and the like becomes one of the new building materials which are developed mainly, and the preparation of the foamed ceramic material with high added value by using the molybdenum tailings becomes a disposal strategy which takes account of the bulk digestion of the molybdenum tailings and the high value of the product, and has important significance. However, the existing foaming ceramic formula takes a Si-Al-Na (K) component system as a main component, silicon aluminum raw materials such as silicon tailings, high-alumina fly ash, ceramic polishing waste and the like can be fully utilized, and the utilization rate of the calcium-rich and magnesium-rich molybdenum tailings is low under the traditional Si-Al-Na (K) component system. How to improve the utilization rate of the molybdenum tailings of the calcium-rich and magnesium-rich components under a novel foaming ceramic component system, breaks the application limit of the traditional ternary system of Si-Al-Na (K) on the calcium-rich and magnesium-molybdenum tailings (and other solid wastes of the same type), and is a key technology with environmental economic benefit and practical value. Disclosure of Invention Aiming at the technical problem that the utilization rate of the existing calcium-rich magnesium-rich molybdenum tailings in Si-Al-Na (K) system foamed ceramics is low, the first aim of the invention is to provide the foamed ceramics prepared by utilizing the calcium-rich magnesium-molybdenum tailings, the foamed ceramics is based on a Si-Al-Mg-Ca component system, the high utilization rate of the molybdenum tailings is realized, other solid waste materials in the area are fully utilized, the utilization rate of the solid waste materials in the foamed ceramics is further improved, the utilization rate of the molybdenum tailings is not lower than 50%, the total solid waste material accounts for not lower than 70%, the volume weight of the prepared foamed ceramics is 400-600kg/m 3, the compressive strength is not lower than 5.0MPa, the heat conductivity coefficient is 0.20-0.35W/(m.K), and the pore structure is uniform. The second aim of the invention is to provide a preparation method of the foamed ceramic prepared by using the calcium-rich magnesium-molybdenum tailings. In order to achieve the above object, the present invention provides the following technical solutions: The invention relates to a foaming ceramic prepared from calcium-rich magnesium-molybdenum tailings, which comprises the following raw materials of 50-70% of molybdenum tailings, 15-25% of fly ash, 10-25% of kaolin, 5-15% of silicon tailings and 2-8% of aluminum oxide, wherein the mass of the foaming agent is 0.4-1.0% of the mass of the base material, and the main chemical composition of the molybdenum tailings is as follows in percentage by mass ：SiO248-55％,MgO 12-18％,CaO 8-13％,Al2O35-10％,Fe2O34-8％,K2O 3-6％. The traditional foaming ceramic raw materials mainly comprise silicon, aluminum and sodium (or potassium), and belong to a Si-Al-Na (K) component system, and calcium, magnesium, iron, potassium and sodium belong to flux components, and the flux components have the function of adjusting the melting temperature and high-temperature liquid phase viscosity of the foaming ceramic blank, so that the content of the flux components is not excessive. The high-calcium high-magnesium molybdenum tailings are mainly characterized in that the high-calcium high-magnesium molybdenum tailings contain more calcium and magnesium elements, cannot be used in a large amount in a Si-Al-Na (K) component system, and the doping amount is often not higher than 10%, so that the application of the high-calcium and magnesium solid waste raw materials in the field of foamed ceramics is greatly limited. The invention skillfully utilizes the characteristics of high calcium and high magnesium molybdenum tailings and high calcium and high magnesium, improves the utilization rate of the high calcium magnesium molybdenum tailings by constructing a Si-Al-Mg-Ca quaternary component system, and the selected auxiliary raw materials are common solid waste raw materials such as fly ash and silicon tailings, so that the aim of multi-solid waste synergy can be realized while the cost of the raw