粘土旧砂湿法再生技术的研究

Study on the Wet Regeneration of Used clay Sand

以含覆膜砂芯砂粘土旧砂为研究对象,对粘土旧砂湿法再生技术进行了研究,确定了湿法再生适宜的工艺路线为"水洗+改性+焙烧",适宜的工艺参数为在1200r/min的转速下擦洗四次,每次擦洗时间为5min,前三次的水砂比为1:1,最后一次的水砂比为0.5:1。对擦洗后的砂子用盐酸进行改性,其加入量为每100g砂子加入0.1mol/L的盐酸标准溶液4mL,然后将改性并烘干后的砂子在600℃下焙烧15min,冷却至室温后制备覆膜砂,其热态抗拉强度为1.246MPa,常温抗拉强度为1.694MPa,均达到或超过了由新砂混制覆膜砂的热态和常温抗拉强度。

Taking the used clay sand containing coated sand as the research object, the wet regeneration technology of used clay sand has been studied in the text. The appropriate process route of ＂water washing＋pickling＋roasting＂ for wet regeneration has been determined. The used sand has been scrubbed four times at the speed of 1200r/min, and each time for scrubbing is 5 minutes. Each of the first three times of water-sand ratios is 1：1, and the last time of water-sand ratio is 0.5：1. The scrubbed sand has been modified with hydrochloric acid in an amount of 4mL of 0.1mol per liter hydrochloric acid standard solution per 100g of sand, and then the modified and dried sand has been roasted at 600℃ for 15 min, and cooled to room temperature for preparation of coated sand. The coated sand has a thermal tensile strength of 1.246 MPa and a tensile strength at room temperature of 1.694 MPa, both of which meet or exceed the thermal and normal temperature resistance of the coated sand by the new mixed coated sand.