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煤粉是湿型铸造时常用的防止铸件粘砂、夹砂，提高铸件表面质量的附加物。但是，由于煤粉危害环境，损害型砂的某些性能，所以国内外相继开展了煤粉代用材料的研究。本文采用差热分析及光亮碳生成率的测试方法对所收集的几十种材料进行了试验，从中优选出了三种，即R1，R2，R3。其中R1和R2具有高的光亮碳生成率，R3可减小型砂的热彭胀。分别测试了这三种材料加入型砂中后对型砂性能的影响，分析结果可知：它们都提高了型砂的热湿拉强度，延长了型砂的爆热开裂时间，减小了型砂的热压应力，提高了型砂的抗夹砂能力。同时它们并不降低型砂的其它性能。用单纯型重心设计，优选出了这三种材料之间最合适的搭配方案。结果表明；对于手工和普通机器造型，由于膨润土加入量较少（5－6％），采用三组之混合物，即R1、R2和R3，在型砂中加入量为1．5～1．7％，而对于气冲和高压造型，膨润土加入量较多（8～10％），仅R1就可满足要求，在型砂中加入量为0．8～1％。
Pulverized coal is commonly used to prevent wetting castings sticky sand, sand, improve the surface quality of castings additions. However, since coal powder is harmful to the environment and some properties of sand are impaired, research on coal substitute materials has been carried out at home and abroad one after another. In this paper, dozens of materials collected were tested by the method of differential thermal analysis and bright carbon formation rate. Three kinds of materials were selected, namely R1, R2 and R3. Among them, R1 and R2 have high bright carbon generation rate, and R3 can reduce thermal bulge of sand. The results show that all of them improve the hot-wet tensile strength of the sand, prolong the detonation cracking time of the sand, reduce the thermal compression stress of the sand, Sand-enhanced anti-sand sand capacity. At the same time they do not reduce the other properties of the sand. Simple center of gravity design, out of the three most suitable materials with the program. The results showed that for the manual and general machine modeling, the mixture of three groups, namely R1, R2 and R3, was added into the sand as 1.5 to 1.7% due to the small amount of bentonite added (5-6%). , While for gas impingement and high pressure modeling, the bentonite is added in large amount (8-10%), only R1 can meet the requirements, and the amount of bentonite added is 0.8-1%.