CN1139072A

CN1139072A - Wet phosphoric acid purifying techn eliminating fluorine and heavy metals

Info

Publication number: CN1139072A
Application number: CN 95105661
Authority: CN
Inventors: 朱运泽; 吴树威; 陈朴; 黄德明; 贾振宇; 周德; 谢伟; 莫桂英
Original assignee: ZHANHUA ENTERPRISES GROUP CO GUANGDONG PROV
Current assignee: ZHANHUA ENTERPRISES GROUP CO GUANGDONG PROV
Priority date: 1995-06-26
Filing date: 1995-06-26
Publication date: 1997-01-01

Abstract

To a conventional semihydrate phosphoric acid prodn apparatus, are added trough and pump filled with defluorating agent and heavy metal eliminating agent, so that fluorine becomes crystal of fluorosilicate and heavy metal becomes preipitation of refractory compound. After filtration, purified phosphoric acid with the P-to-F ratio not lower than 100 and the heavy metal molecule content less than 0.002 is obtained to meet the need of calcium hydrogen phophate prodn.

Description

Wet phosphoric acid purifying defluorinate, removing heavy metals technology

The invention belongs to a kind of wet phosphoric acid purifying defluorinate, removing heavy metals technology.

At present, it is raw material that the defluorination method of phosphoric acid by wet process has the phosphoric acid by wet process that adopts half water or two water conservancy projects skill to produce, and sets up a cover defluorinate device, adds defluorinating agent, through sedimentation, filter, after Fluoride Separation, just obtain meeting the phosphoric acid of producing calcium hydrophosphate fodder, its investment is big, defluorinate cost height.Removing heavy metals in the phosphoric acid production device adds sulfide in the employing phosphoric acid by wet process that has, and the heavy metal in the phosphoric acid is removed obtained meeting the phosphoric acid of producing calcium hydrophosphate fodder, but also will rebuild a cover removing heavy metals device, and is very uneconomical.

The purpose of this invention is to provide a kind of wet phosphoric acid purifying defluorinate, removing heavy metals technology, promptly be in original half water phosphoric acid production device, increase groove and pump that some are equipped with defluorinating agent, removing heavy metals agent, and in production equipment, add defluorinating agent ABS and removing heavy metals agent ABM, make P/F in the phosphoric acid by wet process 〉=100, heavy metal P ²⁺ _b%＜0.002 is met the purifying phosphoric acid of secondary calcium phosphate production requirement.

The present invention is in half water phosphoric acid plant, adds defluorinating agent ABS, removing heavy metals agent ABM, makes purifying phosphoric acid satisfy the requirement that calcium hydrophosphate fodder is produced.In the filtration feeding trough (2) of half water phosphoric acid plant (1), with pump (5) defluorinating agent in the groove (3) is delivered to groove (2) and with pump (6) groove (2) delivered in the removing heavy metals agent in the groove (4), fluorine is with the form crystallization of silicofluoride, the insoluble compound form precipitation of heavy metal gets F%=0.14, P ²⁺ _b%＜0.002 purifies slip, will purify slip again by filter (7), and crystallization and throw outs such as elimination gypsum make P/F in the phosphoric acid of producing 〉=100, heavy metal P ²⁺ _b%＜0.002, the add-on 1-3 of defluorinating agent ABS times, the add-on of removing heavy metals agent ABM is 2-5 times, temperature of reaction: 65～100 ℃, the residence time: 15～50 minutes, reaction pressure: 0.8 * 10 ⁵～2 * 10 ⁵Handkerchief.

The present invention increases by two groove and pumps of adorning defluorinating agent ABS and removing heavy metals agent ABM at Yuan Banshui phosphoric acid production device, just can produce P/F 〉=100, P in preferred ratio adding defluorinating agent ABS and removing heavy metals ABM ²⁺ _bThe purifying phosphoric acid of %＜0.002 meets the requirement of producing calcium hydrophosphate fodder.

Description of drawings:

Fig. 1 is a flow diagram of the present invention.

The present invention utilizes the production equipment of original half water phosphoric acid to develop new product, and phosphoric acid is carried out defluorinate, removing heavy metals, makes P/F 〉=100 behind the wet phosphoric acid purifying, heavy metal P ²⁺ _b%＜0.002, meet the requirement of phosphoric acid preparing calcium hydrophosphate fodder, defluorinating agent ABS is preferably than being 1.2～2.2 times, be contained in the groove (3), be extracted in the slurry vessel (2) with pump (5), and removing heavy metals agent ABM is contained in the groove (4) preferably than 2.5～3.5, be extracted in the slurry vessel (2) with pump (6), the ABS that preferably adds 1.8 times, 3 times ABM, pressure are little negative pressure, temperature is 90 ℃, 20 minutes residence time made the form crystallization of fluorine with silicofluoride, the insoluble compound form precipitation of heavy metal, send to filtration together with slip, utilize filter (7) when filtering gypsum, with these crystallizations and throw out elimination, the F% in slip is 0.83, slip after the purification is 0.15, and heavy metal is (with P ²⁺ _bMeter) % is 0.0035 in slip, and purifying the back slip is 0.0015, need not establish device, low, the remarkable in economical benefits of cost in addition with present method defluorinate, removing heavy metals, adapts to phosphoric acid plant production product innovation and uses.

Claims

1, a kind of wet phosphoric acid purifying defluorinate, removing heavy metals technology, be in half water phosphoric acid plant, add defluorinating agent ABS, removing heavy metals agent ABM, purifying phosphoric acid, satisfy the requirement that calcium hydrophosphate fodder is produced, it is characterized in that: in the filtration feeding trough (2) of half water phosphoric acid plant (1), with pump (5) defluorinating agent in the groove (3) is delivered to groove (2) and with pump (6) groove (2) delivered in the removing heavy metals agent in the groove (4), fluorine is with the form crystallization of silicofluoride, the insoluble compound form precipitation of heavy metal gets F%=0.14, P ²⁺ _b+ %0.002 purifies slip, will purify slip again by filter (7), and crystallization and throw outs such as elimination gypsum make P/F in the phosphoric acid of producing 〉=100, heavy metal P ²⁺ _b%＜0.002, the add-on 1-3 of defluorinating agent ABS times, the add-on of removing heavy metals agent ABM is 2-5 times, temperature of reaction: 65～100 ℃, the residence time: 15～50 minutes, reaction pressure: 0.8 * 10 ⁵～2 * 10 ⁵Handkerchief.