GB190100393A - Improvements in Electrolysis and Apparatus therefor. - Google Patents

Abstract

393. Newton, P. A., [National Electrolytic Co.]. Jan. 7. Alkaline chlorates.-Relates to a process and apparatus for electrolysing solutions, particularly for preparing sodium and potassium chlorates. The electrolyte flows continuously through the cell. The electrodes are in close proximity to one another, about one-sixteenth to oneeighth of an inch apart, and are insulated from one another, but otherwise only separated by the liquid itself. The current employed is about 2 to 4 ampÞres per square inch of electrode surface, and the capacity of a cell is from 2 to 4 cubic inches per square inch of electrode surface. The result of this is that the current itself raises the electrolyte to the required temperature, namely, between 90‹ and 200‹ F., and preferably between 110‹ and 120‹ F. The temperature may be controlled by regulating the rate of flow of the liquid, whether the source of heat be the current itself, or wholly or partly external to the cell. The solution obtained is very weak, preferably containing less than 3 per cent. of chlorate. Several cells are built up together, through which the current is passed in series. In the example shown, each cell is made of a frame A having a metallic resisting lining B. One side is constructed of a metallic-plate D faced with platinum or other non- attackable material E and forming the anode. At the other side there are a number of vertical parallel rods or wires C, preferably of copper, which form the cathode and prevent polarization. They are separated from the opposing anode by horizontal insulating-rods O. The solution is charged through tubes G reaching to near the bottom of the cell, and overflows through the outlet H. The hydrogen developed rises freely up the rods or wires, and also escapes through the outlet H. A number of these cells are connected together by plates K, J and bolts L, a gasket F being placed between each pair of cells to insulate the opposing anode and cathode. The first and last cells are connected up to the two leads. The weak chlorate solution obtained is led away to a cooling-vessel, in which the chlorate separates. The solution is then pumped up to a tank, where it mixes with fresh salt, and is again led to the electrolysing-cells. If a chlorate, such as that of sodium, is produced which is more soluble than the corresponding chloride, the latter is separated out by crystallization, and the chlorate obtained by evaporating the solution left.