钼尾矿是钼矿石经过选矿后剩余的固体废弃物。我国钼资源储量居世界第一、但钼 矿石的品位低，品位超过 0.3%的富矿储量仅占总储量的 1%，因此产生大量钼尾矿。钼 尾矿的堆积不仅占用了大量的土地资源，还破坏了矿区的生态环境，所以对钼尾矿进行 资源化利用非常必要。本文以钼尾矿和水泥为主要原材料，通过化学发泡法制备高掺量 钼尾矿水泥基保温材料，根据钼尾矿的基本性质，具体分为两个子课题：（1）利用钼尾 矿砂直接制备钼尾矿泡沫混凝土自保温砌块；（2）通过将钼尾矿砂粉磨成活性较高的钼 尾矿粉，利用钼尾矿粉制备钼尾矿水泥基泡沫保温板。 

  本文的主要研究内容及结论如下：

（1）首先研究了钼尾矿的基本性质及其反应活性，通过 XRD、XRF 和筛分试验分 析可知：钼尾矿的化学组成中 SiO₂ 含量高达 71.40%，主要以石英形式存在，细度模数 为 1.07，属于特细砂，因此，钼尾矿可以作为硅质材料用于建筑材料的制备。通过不同 掺量钼尾矿对胶凝材料力学性能的影响来确定钼尾矿的最优掺量，当钼尾矿掺量为 30% 时，胶砂块抗压强度比值为 75%，具有一定的水化活性，因此确定钼尾矿掺量为 30%。 掺加钼尾矿后胶凝材料的标准稠度、初凝及终凝时间均随钼尾矿掺量的增加而增加，可 见钼尾矿的活性较低。低活性的钼尾矿可以用于制备自保温砌块，而泡沫保温板对原材 料活性要求较高，因此需要对钼尾矿进行机械活化。试验确定最佳粉磨时间为 60 min， 此时活性指数为 113%，钼尾矿粉的比表面积为 553 m² /kg，D₅₀为 9.40 μm。 

（2）以 30%钼尾矿和 P·O 52.5 水泥为主要原料，采用化学发泡法制备钼尾矿泡沫 混凝土自保温砌块。通过单因素及正交试验，研究了水胶比、发泡剂掺量、水温、硬脂 酸钙掺量对钼尾矿泡沫混凝土性能的影响。结果表明：发泡剂掺量对钼尾矿泡沫混凝土 干密度、抗压强度和平均孔径影响较大，硬脂酸钙对其体积吸水率影响较大。正交试验 确定钼尾矿泡沫混凝土的最优配比为水胶比 0.43、发泡剂 2.0%、水温 40 ℃、硬脂酸钙 0.50%，此时制备的泡沫混凝土干密度为 712 kg/m³，7 d 和 28 d 的抗压强度分别为 4.58 MPa 和 5.54 MPa，体积吸水率为 12.1%，平均孔径为 0.56 mm，孔隙率为 66.2%，导热 系数为 0.178 W/(m·K)，最优配比所制备试块的性能达到 JC/T 2550-2019《泡沫混凝土自保温砌块》密度等级 700、强度 A5.0、体积吸水率应小于 28%的要求。 

（3）对钼尾矿进行机械活化和化学活化，掺加 30%钼尾矿粉制备水泥基泡沫保温 板。硫酸钠的加入可以提高其抗压强度，但当硫酸钠掺量超过 2.0%时抗压强度增长不明 显；发泡剂掺量由 6.0%增加到 7.5%，钼尾矿泡沫保温板干密度由 212 kg/m³减小到 167 kg/m³，孔径和孔隙率随之增大，但发泡剂掺量超过 7.0%时，钼尾矿泡沫保温板内部连通孔的数量和面积均增大，导致体积吸水率和导热系数增大；钼尾矿泡沫保温板的孔结构和孔隙率可通过浆体粘稠度、发泡剂掺量及硬脂酸钙掺量这三个因素相互配合进行调 整。试验确定最优配比为：水胶比 0.45，减水剂 0.45%，硫酸钠 2.0%，发泡剂 7.0%，硬 脂酸钙 1.75%，水温 45 ℃，此时试样干密度为 175 kg/m³，7 d 和 28 d 抗压强度分别为 0.24 MPa 和 0.33 MPa，导热系数为 0.054 W/(m·K)，体积吸水率为 6.9%，干燥收缩值为 3.46 mm/m，均满足 JC/T 2200-2013《水泥基泡沫保温板》标准中 I 型泡沫保温板的要求。

（4）高掺量钼尾矿建筑保温材料研究和应用对于解决钼尾矿的高附加值利用具有 重要的现实意义。大宗利用钼尾矿可以实现环境保护和再生资源利用共赢，符合国家可 持续发展战略，为钼尾矿的高效利用开辟了一条新的技术途径。经过成本分析可知，钼 尾矿自保温砌块的生产成本为 269 元/m³，钼尾矿泡沫保温板的生产成本为 106 元/m³。

Molybdenum tailings are the residual solid waste of molybdenum ore after beneficiation. The reserves of molybdenum resources in my country rank first in the world, but the grade of molybdenum ore is low, and the reserves of rich ore with a grade of more than 0.3% only account for 1% of the total reserves, so a large number of molybdenum tailings are produced. The accumulation of molybdenum tailings not only occupies a large number of land resources but also destroys the ecological environment of the mining area, so the resource utilization of molybdenum tailings is very important. In this paper, molybdenum tailings and cement are used as the main raw materials, and high content molybdenum tailings cement-based thermal insulation materials are prepared by the chemical foaming method. According to the basic properties of molybdenum tailings, it is divided into two sub-topics: 1. Using molybdenum tailings sand to directly prepare molybdenum tailings foam concrete self-insulating blocks; 2. By grinding molybdenum tailing sand into molybdenum tailing powder with higher activity, and using molybdenum tailing powder to prepare molybdenum tailings foam insulation board.

The main research contents and conclusions of this paper are as follows:

(1) The basic properties and reactivity of molybdenum tailings were firstly studied. Through XRD, XRF and gradation test analysis, it can be seen that the chemical composition of molybdenum tailings has a SiO₂ content of up to 71.40%, mainly in the form of quartz, and the fineness modulus is 1.07, which belongs to ultra-fine sand. Therefore, molybdenum tailings can be used as siliceous materials for the preparation of building materials. The optimal dosage of molybdenum tailings was determined by the influence of different dosages of molybdenum tailings on the mechanical properties of cementitious materials. When the dosage of molybdenum tailings was 30%, the ratio of compressive strength of mortar block was 75%, which had certain hydration activity, so the content of molybdenum tailings was determined to be 30%. The standard consistency, initial setting time and final setting time of cementitious materials after adding molybdenum tailings all increased with the increase of molybdenum tailings content, indicating that the activity of molybdenum tailings was low. Molybdenum tailings with low activity can be used to prepare self-insulating blocks, but foam insulation boards have higher requirements on the activity of raw materials. So it is necessary to mechanically activate molybdenum tailings. The optimum grinding time was 60 min, and the activity index was 113%. The specific surface area of molybdenum tailings powder was 553 m² /kg, and the D₅₀ was 9.40 μm. 

(2) Using 30% molybdenum tailings and P·O 52.5 cement as the main raw materials, the self-insulating blocks of molybdenum tailings foam concrete were prepared by the chemical foaming method. The effects of water-cement ratio, foaming agent content, water temperature and calcium stearate content on the properties of molybdenum tailings foamed concrete were studied through single factor and orthogonal experiments. The results showed that the dosage of foaming agent had a great influence on the dry density, compressive strength, and average pore size of molybdenum tailings foam concrete, and the dosage of calcium stearate had a great influence on its volume water absorption. Orthogonal experiments determined that the optimal ratio of molybdenum tailings foam concrete was water-cement ratio 0.43, foaming agent 2.0%, water temperature 40 ℃, calcium stearate 0.50%, and the dry density of foam concrete prepared was 712 kg/m³ , the compressive strengths of 7 d and 28 d were respectively 4.58 MPa and 5.54 MPa, the volume water absorption was 12.1%, the average pore size was 0.56 mm, the porosity was 66.2%, and the thermal conductivity was 0.178 W/(m·K). The performance of the block prepared with the optimal ratio met the requirements of JC/T 2550-2019 for density 700, strength A5.0, and volume water absorption should be less than 28%.

(3) The molybdenum tailings were mechanically and chemically activated, and 30% molybdenum tailings powder was added to prepare cement-based foam insulation board.. The addition of sodium sulfate can improve its compressive strength, but the increase of compressive strength was not obvious when the content of sodium sulfate exceeded 2.0%. When the foaming agent content increased from 6.0% to 7.5%, the dry density of molybdenum tailings foam insulation board decreased from 212 kg/m³ to 167 kg/m³ , and the pore size and porosity increased. However, when the foaming agent content exceeded 7.0%, the number and area of connected pores in the molybdenum tailings foam insulation board increased, which led to the increase of the volume water absorption and thermal conductivity. The pore structure and porosity of molybdenum tailings foam insulation board can be adjusted by the combination of slurry viscosity, foaming agent content and calcium stearate content. Experiments determined that the optimal ratio was: water cement ratio 0.45, water reducing agent 0.45%, sodium sulfate 2.0%, foaming agent 7.0%, calcium stearate 1.75%, water temperature 45 ℃, the dry density of the sample was 175 kg/m³ , the compressive strength of 7 d and 28 d were respectively 0.24 MPa and 0.33 MPa, the thermal conductivity was 0.054 W/(m·K), the volume water absorption rate was 6.9%, and the drying shrinkage value was 3.46 mm/m, all met the requirements of the I-type foam insulation board in the JC/T 2200-2013.

(4) The research and application of building insulation materials with high content of molybdenum tailings have important practical significance for solving the high value-added utilization of molybdenum tailings. Mass use of molybdenum tailings can achieve win-win situation of environmental protection and utilization of renewable resources, which is in line with the national sustainable development strategy and opens up a new technical way for the efficient use of molybdenum tailings. The cost analysis showed that the production cost of molybdenum tailings self-insulation block was 269 yuan/m³ , and the production cost of molybdenum tailings foam insulation board was 106 yuan/m³ .