Abstract:
The invention relates to a process of abatement of the organic content of a depleted brine coming from epoxy compound production involving a vapour stripping step and a mineralisation with hypochlorite in two steps, at distinct pH and temperature conditions.
Abstract:
The invention relates to an amalgam decomposer for mercury cathode chlor-alkali cells. The amalgam decomposer of the invention contains a filling of carbon steel rings whose external surface is provided with a catalytic coating for amalgam decomposition consisting of one or more electrically conductive metals carbides. The internal surface of the rings is free of catalytic coating and wettable by the amalgam, while the external carbide catalytic coating is not wettable by the amalgam thereby favouring hydrogen evolution.
Abstract:
The invention relates to a device for breaking the electrical continuity of the stream of caustic soda produced in mercury-cathode chlor-alkali plants. The device is comprised of a vessel internally subdivided into three compartments by two flow-conveying septa, the three compartments being in communication and defining a caustic soda tortuous flow-path allowing the centrifugal deposition of mercury microdroplets released by the upstream amalgam decomposer.
Abstract:
The invention relates to a porous separator deposited on the cathode body of a diaphragm electrochemical cell, characterised by a predefined roughness profile obtained by vacuum sucking of a suspension containing fibres and an optional particulate material. The degree of vacuum is adjusted in continuous as a function of the percentage of deposited material, preferably by means of a central processing unit acting on the suspension flow. The porosity profile to be obtained is selected depending on the composition of the suspension and the projected industrial operative conditions. The porous separator may be formed by the superposition of a multiplicity of polymer fibre planes comprising primary pores generated by the interconnection of a multiplicity of primary interstices between said fibres, the size of said primary pores having an average value of 2 to 10 μm with a standard deviation not higher than 50 % of said average value.
Abstract:
The invention relates to a synthetic diaphragm for chlor-alkali cells with improved energy consumption and gas separation characteristics. The diaphragm consists of a network of polymer fibres bound to a hydrophilic ceramic material containing zirconium chemically bound to hydroxyl groups. The ceramic material is obtained starting from ZrO 2 by a process of hydration under vacuum which can be carried out directly in the cell by means of a suitable equipment.
Abstract:
The invention relates to an inlet and outlet end-box design for mercury cathode chlor-alkali electrolysis cells of extended lifetime, comprising a composite mechanical structure consisting of a carbon steel bottom entirely supporting the mechanical solicitations, a plastic cover a hydraulic head device for washing the mercury and the amalgam. The device is partially extractable thereby allowing the withdrawal of foreign materials accumulated during operation with no need for opening the end-boxes.