Process for removal of arsenic from elemental phosphorus
AssigneeFMC Corporation
InventorLouis T. Gunkel
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Abstract
Arsenic is removed from elemental phosphorus by treating it with an oxidized form of iodine in a sufficient amount and for a sufficient time to obtain the amount of arsenic reduction desired. When iodine is the source of the oxidized iodine an oxidant is additionally used. An oxidant is optionally used when an oxidized iodine is used. The oxidant also reduces the amount of antimony present in the elemental phosphorus, and a dilute oxidant rinse removes any residual iodine source and also results in a water-white liquid phosphorus.
Claims28
A process for reducing the arsenic content of elemental phosphorus comprising arsenic, the process comprising:
- contacting the elemental phosphorous with an oxidant and with an oxidized form of iodine;
- in which:
- the contacting is carried out at a temperature at which the elemental phosphorous is in the liquid state;
- and
- the contacting is carried out in a manner that prevents the elemental phosphorous from coming in contact with oxygen.
A process for reducing the arsenic content of elemental phosphorus containing arsenic comprising in a closed reactor system
- contacting the elemental phosphorus with an oxidized form of iodine in an amount equivalent to about 0.1-1 weight percent iodine based on the weight of elemental phosphorus and
- contacting the elemental phosphorus with a peroxy compound in an amount of about 0.05-2.4 weight percent based on active oxygen
- wherein the temperature of the process results in the phosphorus being in a liquid state and wherein the contacting is conducted in a manner which prevents the phosphorus from coming into contact with oxygen.
Dependencies are inferred from the claim text.