Production of fluid fertilizer from phosphorus furnace waste stream

A process for the production of fluid fertilizer comprising the steps of:

• (a) smelting phosphatic minerals with coke and silica rock in a submerged arc electric furnace, wherein a phosphorus containing gas is evolved from the furnace;
• (b) cleaning said gas in an electrostatic precipitator;
• (c) condensing phosphorus from said gas by cooling of the gas by direct contact of the gas with water;
• (d) continuously recirculating said water to the condensing step and bleeding off the water at the rate of about 5 gpm per 100 tons of phosphorus produced per day, such liquid containing ppm of elemental phosphorus of the order of 1700 ppm;
• (e) subjecting the bled water from step (d) to a clarifier with about 98 percent of the feed liquid recovered as clarified overflow and about 2 percent recovered as underflow, with about 120 ppm of elemental phosphorus in the overflow;
• (f) treating the clarifier overflow in a centrifuge to remove additional suspended phosphorus and obtain water with about 12 ppm of elemental phosphorus;
• (g) adding the clarified and centrifuged water to fluid fertilizer processes for cooling or dissolution of fertilizer solids;
• wherein:
• the step (g) adding the water to fluid fertilizer processes includes two stage ammoniation using two ammoniators in series, comprising the steps of:
• (1) placing the clarified water from the centrifuge in the two ammoniators, the first of which is equipped with an evaporative cooler;
• (2) adding phosphoric acid to the first stage ammoniator;
• (3) adding a suspending clay to the fluid of the fluid fertilizer process;
• (4) agitating with ammonia in both ammoniators, to produce as a product 11-39-0 orthophosphate base suspension fertilizer.