Process for the production of yellow phosphorus

A process for the production of yellow phosphorus from a charge consisting essentially of natural phosphates and mineral quartzite in an installation comprising an apparatus for the preliminary melting of said charge into a melt collector and which apparatus communicates, through said melt collector, with an electrothermal furnace containing a plurality of electrodes in contact with said melt, comprising:

• a. comminuting phosphate raw materials having a grading not exceeding 50 mm. and quartzite into a finely divided state and mixing together said comminuted phosphates and quartzite to obtain a two-component phosphate-quartzite charge;
• b. melting said two-component phosphate-quartzite charge using fuel combustion products in said apparatus for preliminary melting of the charge;
• c. treating the resulting phosphate-quartzite melt, while flowing down the apparatus walls in a thin layer, with overheated steam obtained from moisture contained in said fuel combustion products to form fluorine compounds;
• d. removing the fluorine compounds and the fuel combustion products from the installation;
• e. continuously feeding the remaining defluorinated melt through said melt collector into said electrothermal furnace;
• f. concurrently with the above steps, feeding to the surface of the melt in the electrothermal furnace a lump reducing agent and, also concurrently, feeding a comminuted reducing agent into the melt layer under pressure, whereby the phosphates in the melt are reduced to yellow phosphorus in gaseous form, together with the formation of furnace gases containing carbon oxide, slag, and ferrophosphorus;
• g. removing the formed slag and ferrophosphorus from the installation;
• and
• h. removing the gaseous mixture of furnace gases and yellow phosphorus from the furnace and condensing the mixture to recover the yellow phosphorus therefrom.

A process for the production of yellow phosphorus comprising:

• a. comminuting a natural phosphate having a grading not exceeding 10 mm. and quartzite into a finely-divided state and mixing together said comminuted phosphates and quartzite to obtain a two-component phosphate-quartzite charge;
• b. melting said two-component phosphate-quartzite charge;
• c. treating the resulting phosphate-quartzite melt, while in a thin layer, with overheated steam to form fluorine compounds;
• d. removing the fluorine compounds;
• e. feeding to the surface of the remaining defluorinated melt a three-component charge consisting essentially of a mixture of heat-treated lump phosphate and quartzite having a grading of about from 10-50 mm., together with a reducing agent having a grading of about from 5-25 mm., while concurrently feeding a comminuted reducing agent into the melt layer under pressure, whereby the phosphates are reduced to yellow phosphorus in gaseous form;
• and
• f. condensing the gaseous yellow phosphorus to recover the yellow phosphorus.

A process for the production of yellow phosphorus comprising:

• a. comminuting phosphate raw materials having a grading not exceeding 50 mm. and quartzite into a finely divided state and mixing together said comminuted phosphates and quartzite to obtain a two-component phosphate-quartzite charge;
• b. melting said two-component phosphate-quartzite charge;
• c. heating the resulting phosphate-quartzite melt, while in a thin layer, with overheated steam to form fluorine compounds;
• d. removing the fluorine compounds;
• e. feeding to the surface of the remaining defluorinated melt a lump reducing agent and concurrently therewith feeding a comminuting reducing agent into the melt layer under pressure, whereby the phosphates are reduced to yellow phosphorus in gaseous form;
• and
• f. condensing the gaseous yellow phosphorus to recover the yellow phosphorus.