Method for producing pig iron and phosphate using ferro-phosphorus

Abstract

A method for producing pig iron and phosphate using ferro-phosphorus is characterized in that: the ferro-phosphorus is arranged in a reverberatory furnace, and performs quick air refining reaction with air or oxygen-rich air, thus the phosphor in the ferro-phosphorus is oxidized into P2O5 gas, and the reaction furnace gas is subjected to heat exchange, dust removal, and P2O5 hydration absorption to obtain rough phosphoric acid, and the rough phosphoric acid is refined and purified to obtain a technical grade phosphoric acid product. While the phosphorus element is oxidized, part of the ferro element is oxidized into ferric oxide, and then the ferric oxide is reacted with the newly-added ferro-phosphorus, thus the phosphorus element is oxidized into the P2O5 gas, and the ferric oxide is reduced into the ferro by phosphorus; when the phosphorus content in the iron solution in the reverberatory furnace is smaller than 4%, the iron solution is arranged in a converter and processed by pig iron smelting after adding refining agent such as burned lime powder as dephosphorization agent, and the eligible pig iron solution is then processed by injection moulding to obtain a pig iron product. The best material reaction temperature in the reverberatory furnace is 1300-1600 DEG C.

Description

technical field [0001] The invention relates to a process for preparing pig iron and phosphoric acid by using ferrophosphorus, which belongs to the field of metallurgy and chemical industry. Background technique [0002] At present, the main process of using ferrophosphorus at home and abroad is: after mixing ferrophosphorus powder and sodium carbonate in a certain proportion, carry out oxidation roasting reaction at 900-1000°C, and the reacted materials are crushed, leached with water, and filtered; filter cake It is iron slime waste residue, and the filtrate is neutralized by adding phosphoric acid, purified, concentrated, crystallized, and dried to obtain sodium phosphate product. This method mainly has the disadvantages of large consumption of sodium carbonate, low phosphorus utilization rate, phosphoric acid consumption, long process flow, certain "three wastes" pollution sources, and poor economic benefits. The patent of "Process of Extracting Vanadium and Smelting Fe...

AI Technical Summary

Problems solved by technology

The main deficiencies in this patent are: high reaction temperature (1600°C-2000°C), high energy consumption, a large amount of volatilized phosphide that is not utilized and pollutes the environment, and phosphorus in the slag is used as phosphate fertilizer, making the phosphorus in iron phosphorus The value is greatly reduced and a lot of iron is wasted

At present, there is no precedent in domestic production of phosphoric acid by ferrophosphorus and its iron element is allowed to be used. The present invention is improved and perfected on the basis of the earlier application number 200610011022. The process cannot be carried out continuously, and the process control requirements are high.

Images