烧结助剂添加对某黄金尾砂制备发泡陶瓷的影响

以黄金尾砂制备发泡陶瓷应用前景广阔，但存在烧结温度过高等问题，烧结助剂的添加可以有效降低发泡陶瓷的烧结温度。以氟硅酸钠和钠长石的混合物为烧结助剂，采用无压粉体烧结法制备黄金尾砂发泡陶瓷，研究了氟硅酸钠和钠长石添加比例对黄金尾砂发泡陶瓷微观形貌、抗压强度、体积密度及显气孔率的影响。结果表明：随着氟硅酸钠所占比例的增加，样品的抗压强度和体积密度均先上升后下降，显气孔率先减小后增大，孔径尺寸和分布的均匀性变好；当氟硅酸钠与钠长石添加比例为5∶3、烧结温度为1 050 ℃时，可以成功制备出体积密度455 kg/m3、抗压强度4.7 MPa、显气孔率21%、气孔分布均匀的黄金尾砂发泡陶瓷。适量添加钠长石可以增加气孔数量，添加过量则会因为高温下低黏度液体含量过高而导致孔结构坍塌；烧结助剂应该以氟硅酸钠为主，根据不同要求添加适量的钠长石以提高显气孔率。

Effect of Sintering Additives Addition on Foamed Ceramics Prepared with a Gold Tailings

The preparation of foamed ceramics with gold tailings has a broad application prospect， but the sintering temperature is too high. The addition of sintering additives can effectively reduce the sintering temperature of foamed ceramics. Using the mixture of sodium fluosilicate and albite as sintering agents， the gold tailings foamed ceramics were prepared by non-pressing powder sintering method. The effects of the addition ratio of sodium fluosilicate and albite on the micromorphology， compressive strength， bulk density and apparent porosity of the gold tailings foamed ceramics were studied. The results showed that with the increase of sodium fluosilicate proportion， the compressive strength and bulk density of the samples firstly increase and then decrease， the apparent porosity firstly decrease and then increase， and the uniformity of pore size and distribution becomes better. When the addition ratio of sodium fluosilicate and albite is 5∶3 and the sintering temperature is 1 050 ℃， the gold tailings foamed ceramics with bulk density of 455 kg/m3， compressive strength of 4.7 MPa， apparent porosity of 21% and uniform porosity distribution can be successfully prepared. Appropriate addition of albite can increase the number of pores， but excessive addition will lead to the collapse of pore structure due to the high content of low viscosity liquid at high temperature. Sodium fluosilicate should be the main sintering agent and albite should be added according to different requirements to improve the apparent porosity.