公开(公告)号：US3907978A

公开(公告)日：1975-09-23

申请号：US44154674

申请日：1974-02-11

Applicant: BAYER AG

Inventor： SPRECKELMEYER BERNHARD

IPC: C01F11/22 ,  G01F11/22 ,  C01B33/12

CPC classification number: C01F11/22

Abstract: In the production of synthetic fluorspar low in SiO2 wherein aqueous hexafluosilicic acid is reacted with calcium carbonate, and the resulting calcium fluoride is filtered off, the improvement which comprises effecting the reaction by adding hexafluosilicic acid to an aqueous suspension of the calcium carbonate at a temperature of about 0* to 40*C, there being present during the reaction at least about 3 times as much water by weight as calcium carbonate. Advantageously the reaction is effected in a plurality of stages, in the first of which the calcium carbonate suspension is reacted with a stoichiometric excess of hexafluosilicic acid up to a pH of about 2 to 3, and after a residence time of about 5 to 30 minutes the pH is adjusted to about 4 to 6 in the second stage by the addition of calcium carbonate.

Abstract translation: 在其中六氟硅酸含量与碳酸钙反应的SiO 2中合成氟化合物的生产中，滤出所得的氟化钙，其改进包括通过在碳酸钙的水悬浮液中加入六氟硅酸进行反应 约0℃至40℃，在反应期间存在的重量比碳酸钙至少约3倍。 有利地，反应在多个阶段中进行，其中第一个阶段使碳酸钙悬浮液与化学计量过量的六氟硅酸反应，直至约2至3的pH，并且在约5至30分钟的停留时间 在第二阶段通过添加碳酸钙将pH调节至约4至6。

公开(公告)号：US3919399A

公开(公告)日：1975-11-11

申请号：US33559673

申请日：1973-02-26

Applicant: BAYER AG

Inventor： SCHABACHER WERNER ,  ROHE HERMANN ,  KELLER WOLFGANG ,  SPRECKELMEYER BERNHARD

IPC: C01B7/19 ,  C01B7/22

CPC classification number: C01B7/191

Abstract: The present invention relates to a process for recovering hydrogen fluoride from the gaseous reaction product of a metal fluoride with sulfuric acid by washing the gaseous product in a first stage with concentrated sulfuric acid and thereby cooling the gas to a temperature of about 60* to 130*C, cooling said gas by indirect heat exchange with water to a temperature of about 30* to 50*C in a second stage and in a third stage by direct heat exchange with pure hydrofluoric acid to a temperature of about 20* to 25*C, condensing hydrogen fluoride in the cooled gaseous product of the third stage in at least two additional stages and recovering condensed hydrogen fluoride.

Abstract translation: 本发明涉及一种从金属氟化物与硫酸的气体反应产物中回收氟化氢的方法，该方法是在第一阶段用浓硫酸洗涤气态产物，从而将气体冷却至约60°至130℃ DEG，通过与水的间接热交换在第二阶段和第三阶段通过与纯氢氟酸直接热交换至约20°至25℃的温度来冷却所述气体 C，在至少两个附加阶段中将第三阶段的冷却的气态产物中的氟化氢冷凝并回收冷凝的氟化氢。