A process for producing amorphous sodium silicates having a water content of 0.3 to 6% by weight and an SiO.sub.2 /Na.sub.2 O molar ratio of (1.9 to 2.8) : 1 from a waterglass solution containing at least 20% by weight of solids, the water-glass solution is obtained by reacting quartz sand with sodium hydroxide solution at an SiO.sub.2 /Na.sub.2 O molar ratio of (2.0 to 2.8) : 1 at temperatures of 180 to 240.degree. C. and pressures of 10 to 30 bar. This waterglass solution is treated in a spray-drying zone with hot air at 200 to 300.degree. C. for a residence time of 10 to 20 seconds and at a temperature of the exit gas leaving the spray-drying zone of 90.degree. to 130.degree. C., to form a pulverulent amorphous sodium silicate having a water content (determined as the loss on ignition at 700.degree. C.) of 15 to 23% by weight and a bulk density of more than 300 g/l. The pulverulent sodium silicate is introduced into an obliquely arranged rotary kiln fitted with devices for moving solids and treated therein with flue gas in countercurrent at temperatures from 250.degree. up to 500.degree. C. for 1 to 60 minutes. The rotary kiln is here insulated in such a way that its outside wall temperature is less than 60.degree. C. Finally, the amorphous sodium silicate emerging from the rotary kiln is comminuted by means of a mechanical crusher to grain sizes of 0.1 to 12 mm.
一种生产无定形
钠硅酸盐的方法,其
水含量为0.3至6重量%,SiO.sub.2 / Na.sub.2 O摩尔比为(1.9至2.8):1,从含有至少20重量%固体的
水玻璃溶液中获得,该
水玻璃溶液是通过在180至240℃和10至30巴的温度和压力下,用
氢氧化钠溶液与
石英砂反应而获得的,SiO.sub.2 / Na.sub.2 O摩尔比为(2.0至2.8):1。在喷雾干燥区域中,将该
水玻璃溶液用200至300℃的热空气处理,停留时间为10至20秒,离开喷雾干燥区域的出气温度为90℃至130℃,形成具有15至23重量%
水含量(在700℃的灼烧失重率确定)和大于300 g / l的松散无定形
钠硅酸盐。将该松散的
钠硅酸盐引入斜置的旋转窑中,并在逆流的烟气中以250℃至500℃的温度进行处理,处理时间为1至60分钟。旋转窑被绝缘,以使其外壁温度低于60℃。最后,从旋转窑中出来的无定形
钠硅酸盐通过机械破碎机粉碎成0.1至12毫米的粒度。