CN100494051C - Technology for preparing fine calcium phosphate using phosphor-gypsum backwater and its wash liquid - Google Patents
Technology for preparing fine calcium phosphate using phosphor-gypsum backwater and its wash liquid Download PDFInfo
- Publication number
- CN100494051C CN100494051C CNB2006100225636A CN200610022563A CN100494051C CN 100494051 C CN100494051 C CN 100494051C CN B2006100225636 A CNB2006100225636 A CN B2006100225636A CN 200610022563 A CN200610022563 A CN 200610022563A CN 100494051 C CN100494051 C CN 100494051C
- Authority
- CN
- China
- Prior art keywords
- calcium phosphate
- fine calcium
- reaction
- phosphate
- terminal point
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Abstract
The invention discloses a phosphogypsum backwater technique and refined calcium phosphate making technique, which is characterized by the following: improving the density of wet process P2O5 from 22-26% to 28-32%; reducing the solubility of P2O5 below 0.3% and soluble fluorine below 0.02%; purifying calcium salt through alkali; filtering to obtain filter pie with high fertilizer graded calcium hydrogen phosphate; using supernatant to make different kinds of refined phosphoric calcium salt; filtering; drying the filter pie to obtain the product.
Description
One, technical field
The technical field that the present invention uses is the production of fine phosphate.
Two, background technology
DAP or MAP production industry, in order to guarantee the concentration of phosphoric acid by wet process, the water balance control of phosphoric acid system is comparatively strict, if the wash water of phosphogypsum surpasses phosphogypsum weight～65%, the phosphoric acid concentration of phosphoric acid extraction system output will drop to below 26% so, for follow-up concentrating increases burden, thereby influence economic benefit of enterprises; If leaching requirement is too small, the water-soluble phosphorus in the phosphogypsum will wash not exclusively, not only can cause the financial loss of enterprise, in the gypsum stacking process, through rainwash, these water-soluble phosphorus will enter the eutrophication that ground water regime causes rivers and lakes, thereby cause environmental pollution.In addition, the minimizing of leaching requirement also causes the soluble fluoride content overproof in the phosphogypsum, causes regional underground water fluorine content overproof, thereby local resident's drinking water safety is threatened.In large-scale phosphate fertilizer manufacturing enterprise, wet deslagging technology is adopted in the discharging of phosphogypsum usually, promptly adopts the part process water that phosphogypsum is starched again, with pump gypsum slurry is sent to the slag field, through after the sedimentation, clear water is got back to the phosphoric acid systemic circulation and is used, and we are referred to as backwater this part water.Dilution gradually along with phosphate rock resource, the crystallization of phosphogypsum is tending towards tiny, because phosphoric acid concentration control is comparatively strict, leaching requirement often can add, and causes water-soluble phosphorus and water-soluble fluorine in the gypsum to exceed standard, again in the slurry process, these water-soluble phosphorus and water-soluble fluorine enter in the pulp-water again, along with the increase of pulp-water cycle index again, phosphorus content wherein progressively increases, generally 1.0～2.0%.How fully effectively utilizing these phosphorus, thereby make the phosphoric acid system weighing apparatus that is up to the standard, is the economic problems that these enterprises are concerned about, also is the major issue of relevant environmental protection.
Do not need Phosphoric Acid Concentration the production of fine calcium phosphate (as calcium hydrophosphate fodder and toothpaste grade calcium hydrophosphate), can from dilute phosphoric acid, be precipitated out fully, more energy-conservation, be a kind of method of effectively utilizing dilute phosphoric acid.The production of fine calcium phosphate at present substantially all is to adopt phosphoric acid by wet process or thermal phosphoric acid production.It is good to adopt thermal phosphoric acid to produce the fine calcium phosphate quality, the purity height, but its production cost is higher, and this operational path is fit to the high calcium phosphate salt that rise in value; And the calcium phosphate salt that utilize phosphoric acid by wet process to produce need carry out impurity and purification to phosphoric acid, just can produce qualified fine calcium phosphate product, and in addition, this process unit investment is big, and profit is low.In existing technology, mainly concentrate on and utilize Wet-process Phosphoric Acid Production calcium hydrophosphate fodder industry, for example CN1107661A, CN1048015A, CN1045423C, CN1049403C, CN1063157C, CN1212263C, CN1281483C, CN1260322A etc. are to improve the patent of being applied on the calcium hydrophosphate fodder production technique.At present, phosphor-gypsum backwater is not handled and is further produced the feasible program of fine calcium phosphate.
Characteristics of the present invention are: when effectively utilizing phosphor-gypsum backwater, can change at present because the same situation that descends of water-soluble phosphate manufacturing enterprise phosphoric acid by wet process concentration that the phosphorus ore grade descends and caused, promptly can be the phosphoric acid (P of present Wet-process Phosphoric Acid Production enterprise
2O
5) concentration brings up to 28～32% from 22～26%, and the water-soluble P in the phosphogypsum
2O
5Drop to below 0.3% from 0.7～1.0% on the contrary, solvable fluorion drops to 0.02% from 0.06～0.09%.
Three, summary of the invention
A kind of technology of utilizing phosphor-gypsum backwater to prepare fine calcium phosphate that the objective of the invention is the serious Financial cost that faced at present Wet-process Phosphoric Acid Production enterprise and problem of environmental pollution and the deficiencies in the prior art and propose.Be characterized in the gypsum that utilizes phosphor-gypsum backwater thorough washing phosphoric acid by wet process device to be produced, make water-soluble phosphorus in the gypsum less than 0.3%, solvable fluorion drops to below 0.02%.The part washing lotion of washing phosphogypsum is returned the phosphoric acid extraction system, and with suitable liquid-solid ratio and the phosphoric acid concentration of control extraction tank, unnecessary washing lotion is isolated extraction system and gypsum backwater and is used for producing fine calcium phosphate together.Mixed solution with phosphor-gypsum backwater and phosphogypsum washing lotion is that the raw material production secondary calcium phosphate is that example illustrates relevant chemical reaction of the present invention below, and wherein these chemical equation are as follows.
Ca
5F(PO
4)
3+5H
2SO
4+10H
2O＝＝3H
3PO
4+5CaSO
4·2H
2O↓+HF↑
Ca
5F(PO
4)
3+7H
3PO
4＝＝5Ca(H
2PO
4)
2+HF↑
Ca(H
2PO
4)
2+H
2SO
4+2H
2O＝＝2H
3PO
4+CaSO
4·2H
2O↓
2H
3PO
4+Ca(OH)
2＝＝Ca(H
2PO
4)
2+2H
2O
Ca(H
2PO
4)
2+Ca(OH)
2+2H
2O＝＝2CaHPO
4·2H
2O↓
2F
-+Ca
2+＝＝CaF
2↓
Fe
3++PO
4 3-+2H
2O＝＝FePO
4·2H
2O↓
Al
3++PO
4 3-+2H
2O＝＝AlPO
4·2H
2O↓
Generally speaking, large-scale Wet-process Phosphoric Acid Production enterprise mostly controls phosphoric acid concentration more than 26%, descends thereby keep away the output that the concentration systems scarce capacity causes.Control higher phosphorous acid concentration must possess two conditions, and the one, the phosphorus ore quality height requires to reach national acid system processing phosphate fertilizer with the class standard (ZBD51001-86) of phosphorus ore promptly: P
2O
5≧ 30.0%, MgO/P
2O
5≦ 2.0%, (Fe
2O
3+ Al
2O
3)/P
2O
5≦ 2.5%, CO
2≦ 3.0%.If phosphorus ore quality is poor, then the phosphogypsum crystal that generates can be relatively poor, and used wash water is then bigger; If Vanadium Pentoxide in FLAKES is low in the phosphorus ore, the acid non-soluble substance height, then the amount of gypsum of Sheng Chenging is bigger, and used leaching requirement also must increase the content that could control the water-soluble phosphorus in the phosphogypsum.The 2nd, to the control of reaction conditions, for different phosphorus ores, suitable reaction conditions can make the crystallization of phosphogypsum thick, and under the certain situation of the water-soluble phosphorus of phosphogypsum, used leaching requirement is less.According to two conditions of the high phosphoric acid concentration of top control, leaching requirement is a key factor.And at present both at home and abroad all Wet-process Phosphoric Acid Production enterprises all can not guarantee to accomplish the low water-soluble phosphorus in the phosphogypsum and the coordinating and unifying of high phosphoric acid concentration simultaneously, so inevitably have higher Vanadium Pentoxide in FLAKES of concentration and water-soluble fluoride in the phosphogypsum of these enterprise's dischargings, the existence of these water soluble ions causes bigger harm to environment.The present invention starts with from this respect just, no matter how the quality of phosphorus ore changes, under the lower situation of water-soluble phosphorus in guaranteeing phosphogypsum, can guarantee concentration of phosphoric acid simultaneously, promptly be used for producing fine calcium phosphate starching Vanadium Pentoxide in FLAKES in the phosphor-gypsum backwater and the Vanadium Pentoxide in FLAKES in the part washing lotion again.
According to the difference of the used phosphorus ore of Wet-process Phosphoric Acid Production enterprise, the mixed solution that phosphor-gypsum backwater and part washing lotion form prepares fine calcium phosphate under following condition.In the mixed solution harmful element and impurity remove reaction conditions: temperature of reaction is: 35～60 ℃, optimum temps is: 40～55 ℃; Reaction times is 0.5～4 hour, and Best Times is 1.5～2.5 hours; Lime milk concentration is: 0～20%CaO, and optimum concn is: 5～15%; In and terminal point PH be controlled at 2.0～3.5.Slip after the purification is through filtering, and filter cake is impure higher fertilizer grade secondary calcium phosphate, and according to the degree of purification difference, clear liquid can be used for further producing fine calcium phosphate.The reaction conditions of fine calcium phosphate is: temperature of reaction is: 40～60 ℃, optimum temps is: 40～50 ℃; Reaction times is 0.5～3 hour, and Best Times is 0.3～1.5 hour; According to the difference of prepared calcium phosphate salt kind, in and terminal point PH be controlled at 5.0～12.0.Reaction finishes after-filtration, and filter cake obtains product through super-dry.
Core technology of the present invention is: can fully effectively utilize the Vanadium Pentoxide in FLAKES in phosphor-gypsum backwater and the unnecessary phosphogypsum washing lotion to prepare fine calcium phosphate.This technology can change at present because the phosphorus ore grade descends, the impurity in the phosphorus ore is too high and enterprise descends to the improper phosphoric acid concentration that causes of phosphoric acid extraction condition control and phosphogypsum in water-soluble phosphorus, the situation that water-soluble fluorine rises, this situation not only can cause the economy downturn of enterprise, also can pollute environment.The present invention can be the phosphoric acid (P of present Wet-process Phosphoric Acid Production enterprise
2O
5) concentration brings up to 28～32% from 22～26%, and the water-soluble P in the phosphogypsum
2O
5Drop to below 0.3% from 0.7～1.0% on the contrary, solvable fluorion drops to 0.02% from 0.06～0.09%.
In prior art, the shortcoming of utilizing thermal phosphoric acid to produce the technology of fine calcium phosphate is: the products production cost is higher, and the market competitiveness is low; And utilize the production equipment investment of fine calcium phosphate of Wet-process Phosphoric Acid Production higher, the payback period is longer.In addition, in existing patented technology, propose at phosphor-gypsum backwater and the technology solution that improves phosphoric acid concentration without any technology.
Purpose of the present invention by following technical measures realize, wherein said raw material umber except that specified otherwise, be parts by weight.
Utilize the part washing lotion of phosphor-gypsum backwater and/or phosphogypsum to prepare the method for fine calcium phosphate, adopt in lime carbonate, calcium oxide or the calcium hydroxide and the part washing lotion of phosphor-gypsum backwater and/or phosphogypsum prepares fine calcium phosphate, described fine calcium phosphate is calcium hydrophosphate fodder, feed-level tricalcium phosphate, food-grade calcium hydrogen phosphate, food grade tricalcium phosphate or toothpaste grade calcium hydrophosphate, it is characterized in that may further comprise the steps:
(1) purifying step
Adopt milk of lime to purify the part washing lotion of described phosphor-gypsum backwater and/or phosphogypsum, reaction conditions is: lime milk concentration 5～15%CaO, 35～60 ℃ of temperature of reaction, 0.5～4 hour reaction times, terminal point pH2.0～3.5; Slip after the purification after filtration, filter cake is the fertilizer grade secondary calcium phosphate, clear liquid is used to prepare fine calcium phosphate;
(2) preparation fine calcium phosphate
Further use in lime carbonate, calcium oxide or the calcium hydroxide and the clear liquid after filtering, reaction conditions is: 40～60 ℃ of temperature of reaction, and 0.5～3 hour reaction times, terminal point pH5.0～12.0, reaction finishes after-filtration, and filter cake obtains fine calcium phosphate through super-dry;
Mother liquor behind the preparation fine calcium phosphate turns back to the phosphoric acid system through purifying as process recycled water.
The reaction conditions of described step (1) is preferably: 40～55 ℃ of temperature of reaction, in 1.5～2.5 hours reaction times, terminal point pH is controlled at 2.4～3.2.
The reaction conditions of described step (2) is preferably: 40～50 ℃ of temperature of reaction, in 0.3～1.5 hour reaction times, terminal point pH is controlled at 5.0～12.0.
The described mother liquor of preparation behind the fine calcium phosphate is with in the milk of lime and purify, and reaction conditions is: 30～60 ℃ of neutral temperatures, in and 0.5～3.0 hour time, terminal point pH=8.0～12.0; Preferred reaction conditions is: 35～50 ℃ of neutral temperatures, in and 0.5～1.0 hour time, terminal point pH=8.0～11.0.
The present invention has following advantage:
Compared with the prior art the present invention can fully effectively utilize the Vanadium Pentoxide in FLAKES in phosphor-gypsum backwater and the unnecessary phosphogypsum washing lotion to prepare fine calcium phosphate.This technology has following 5 contributions concerning manufacturing enterprise and society, and the one, can fully effectively utilize the free phosphorus element that from phosphorus ore, has extracted, improve resource utilization; The 2nd, can effectively improve the phosphoric acid concentration of Wet-process Phosphoric Acid Production enterprise, for enterprise's Synergistic and energy-saving is given security; The 3rd, reduction enterprise produces water-soluble phosphorus and the water-soluble fluorine in the phosphogypsum, reduces the pollution of phosphogypsum stacking to environment; The 4th, for enterprise increases a fine phosphate kind, the variation of phosphoric acid salt kind can strengthen the ability that enterprise resists the market risk; The 5th, provide technical support for creating conservation-minded society.The present invention not only can keep the existing suitable phosphoric acid concentration of Wet-process Phosphoric Acid Production enterprise, simultaneously also can be the phosphoric acid (P of present Wet-process Phosphoric Acid Production enterprise
2O
5) concentration brings up to 28～32% from 22～26%, and the water-soluble P in the phosphogypsum
2O
5Drop to below 0.3% from 0.7～1.0% on the contrary, solvable fluorion drops to 0.02% from 0.06～0.09%.
Four, description of drawings
Fig. 1 prepares the fine calcium phosphate flow diagram for utilizing phosphor-gypsum backwater and washing lotion thereof.
Five, embodiment
Below by embodiment the present invention is specifically described; be necessary to be pointed out that at this present embodiment only is used for the present invention is further specified; but can not be interpreted as limiting the scope of the invention, the person skilled in the art in this field can improve and adjust according to some nonessential contents in the foregoing invention.
Embodiment 1
Phosphor-gypsum backwater (is contained P
2O
5Be 1.3%) 500 the gram with 1500 the gram the phosphogypsum washing lotions (contain P
2O
512%) mixes, utilize milk of lime to purify and the preparation calcium hydrophosphate fodder.The purification reaction conditions is: 50 ℃ of temperature, and time 1.5hr, terminal point PH are 2.8; Purify after-filtration, filter cake is the secondary calcium phosphate of fertilizer grade; Filtrate being used for prepares calcium hydrophosphate fodder, and concrete reaction conditions is: 40 ℃ of temperature, time 1hr, terminal point PH are 6.2, react the after-filtration that finishes, and are finished product behind the filtration cakes torrefaction.The test-results data see the following form.
Embodiment 2
Take by weighing phosphor-gypsum backwater and (contain P
2O
5Be 1.3%) 5000 grams, utilize Paris white to purify backwater, and with preparing calcium hydrophosphate fodder with scavenging solution in the milk of lime.The purification reaction conditions is: 40 ℃ of temperature, and time 1.5hr, terminal point PH are 2.9; Purify after-filtration, filter cake is the secondary calcium phosphate of fertilizer grade; Filtrate is used in the milk of lime and the preparation calcium hydrophosphate fodder, and concrete reaction conditions is: 45 ℃ of temperature, time 1hr, terminal point PH are 6.2, react the after-filtration that finishes, and are finished product behind the filtration cakes torrefaction.The test-results data see the following form.
Embodiment 3
Phosphor-gypsum backwater (is contained P
2O
5Be 1.3%) 1000 the gram with 1000 the gram the phosphogypsum washing lotions (contain P
2O
512%) mix, utilize Paris white to purify mixed solution, and with preparing calcium hydrophosphate fodder with scavenging solution in the milk of lime.The purification reaction conditions is: 50 ℃ of temperature, and time 1.5hr, terminal point PH are 2.75; Purify after-filtration, filter cake is the secondary calcium phosphate of fertilizer grade; Filtrate being used for prepares calcium hydrophosphate fodder, and concrete reaction conditions is: 45 ℃ of temperature, time 1hr, terminal point PH are 6.3, react the after-filtration that finishes, and are finished product behind the filtration cakes torrefaction.The test-results data see the following form.
Embodiment 4
Take by weighing phosphor-gypsum backwater and (contain P
2O
5Be 1.3%) 5000 grams, utilize Paris white to purify backwater, and with preparing feed-level tricalcium phosphate with scavenging solution in milk of lime and the ammoniacal liquor.The purification reaction conditions is: 45 ℃ of temperature, and time 2.0hr, terminal point PH are 2.8; Purify after-filtration, filter cake is the secondary calcium phosphate of fertilizer grade; Filtrate is used in milk of lime and the ammoniacal liquor and the preparation feed-level tricalcium phosphate, and concrete reaction conditions is: 45 ℃ of temperature, time 2hr, the newborn neutral terminal point PH of ash is 7.7, then adopt in the ammoniacal liquor and PH to 11, react the after-filtration that finishes, be feed-level tricalcium phosphate behind the filtration cakes torrefaction.The test-results data see the following form.
Claims (5)
1. utilize the part washing lotion of phosphor-gypsum backwater and/or phosphogypsum to prepare the method for fine calcium phosphate, adopt in lime carbonate, calcium oxide or the calcium hydroxide and the part washing lotion of phosphor-gypsum backwater and/or phosphogypsum prepares fine calcium phosphate, described fine calcium phosphate is calcium hydrophosphate fodder, feed-level tricalcium phosphate, food-grade calcium hydrogen phosphate, food grade tricalcium phosphate or toothpaste grade calcium hydrophosphate, it is characterized in that may further comprise the steps:
(1) purifying step
Adopt milk of lime to purify the part washing lotion of described phosphor-gypsum backwater and/or phosphogypsum, reaction conditions is: lime milk concentration 5～15%CaO, 35～60 ℃ of temperature of reaction, 0.5～4 hour reaction times, terminal point pH2.0～3.5; Slip after the purification after filtration, filter cake is the fertilizer grade secondary calcium phosphate, clear liquid is used to prepare fine calcium phosphate;
(2) preparation fine calcium phosphate
Further use in lime carbonate, calcium oxide or the calcium hydroxide and the clear liquid after filtering, reaction conditions is: 40～60 ℃ of temperature of reaction, and 0.5～3 hour reaction times, terminal point pH5.0～12.0, reaction finishes after-filtration, and filter cake obtains fine calcium phosphate through super-dry;
Mother liquor behind the preparation fine calcium phosphate turns back to the phosphoric acid system through purifying as process recycled water.
2. the method for preparing fine calcium phosphate according to claim 1, the reaction conditions of wherein said step (1) is: 40～55 ℃ of temperature of reaction, 1.5～2.5 hours reaction times, terminal point pH2.4～3.2.
3. the method for preparing fine calcium phosphate according to claim 1, the reaction conditions of wherein said step (2) is: 40～50 ℃ of temperature of reaction, 0.3～1.5 hour reaction times, terminal point pH5.0～12.0.
4. the method for preparing fine calcium phosphate according to claim 1, wherein prepare described mother liquor behind the fine calcium phosphate with in the milk of lime and purify, reaction conditions is: 30～60 ℃ of neutral temperatures, in and 0.5～3.0 hour time, terminal point pH=8.0～12.0.
5. the method for preparing fine calcium phosphate according to claim 4, wherein prepare described mother liquor behind the fine calcium phosphate with in the milk of lime and purify, reaction conditions is: 35～50 ℃ of neutral temperatures, in and 0.5～1.0 hour time, terminal point pH=8.0～11.0.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100225636A CN100494051C (en) | 2006-12-21 | 2006-12-21 | Technology for preparing fine calcium phosphate using phosphor-gypsum backwater and its wash liquid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100225636A CN100494051C (en) | 2006-12-21 | 2006-12-21 | Technology for preparing fine calcium phosphate using phosphor-gypsum backwater and its wash liquid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1994872A CN1994872A (en) | 2007-07-11 |
| CN100494051C true CN100494051C (en) | 2009-06-03 |
Family
ID=38250094
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006100225636A Expired - Fee Related CN100494051C (en) | 2006-12-21 | 2006-12-21 | Technology for preparing fine calcium phosphate using phosphor-gypsum backwater and its wash liquid |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100494051C (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102040206A (en) * | 2010-11-02 | 2011-05-04 | 昆明川金诺化工有限公司 | Method for recycling acid sludge produced by concentrated phosphoric acid |
| CN102849703B (en) * | 2012-09-07 | 2014-03-19 | 四川大学 | Method for preparing fine calcium phosphate by using phosphogypsum desulfurization residue |
| CN102923680A (en) * | 2012-11-30 | 2013-02-13 | 瓮福（集团）有限责任公司 | Method for replenishing diammonium phosphate washing liquor with phosphorus-containing pool water |
| CN103213962B (en) * | 2013-04-19 | 2015-05-06 | 武汉工程大学 | Method for preparing feed-grade calcium hydrophosphate from phosphoric acid-containing mixed acid etching waste liquid |
| CN103303884A (en) * | 2013-05-27 | 2013-09-18 | 瓮福（集团）有限责任公司 | Method for treating phosphorus concentrates and recovering phosphorus by using phosphogypsum slag dump pool water |
| CN103553722A (en) * | 2013-10-24 | 2014-02-05 | 瓮福（集团）有限责任公司 | Method for preparing super phosphate by use of ardealite slag site sewage |
| CN106186601B (en) * | 2016-07-26 | 2019-02-26 | 四川高绿平环境科技有限公司 | A kind of processing method of sludge |
| CN109809551A (en) * | 2019-03-26 | 2019-05-28 | 中化重庆涪陵化工有限公司 | A kind of phosphor-gypsum backwater reutilization system |
| CN112978781A (en) * | 2021-04-13 | 2021-06-18 | 中国五环工程有限公司 | Phosphogypsum harmless treatment method |
| CN114291857A (en) * | 2021-12-23 | 2022-04-08 | 贵州蓝图新材料股份有限公司 | Chemical purifying liquid pumping and pressure filtering synthesis process |
| CN115557719B (en) * | 2022-08-16 | 2023-08-15 | 湖北祥云(集团)化工股份有限公司 | Comprehensive treatment method of phosphogypsum |
-
2006
- 2006-12-21 CN CNB2006100225636A patent/CN100494051C/en not_active Expired - Fee Related
Non-Patent Citations (2)
| Title |
|---|
| 磷复肥及磷酸盐工艺学. 王励生，万先达，廖华书，276-287，成都科技大学出版社. 1993 |
| 磷复肥及磷酸盐工艺学. 王励生，万先达，廖华书，276-287，成都科技大学出版社. 1993 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1994872A (en) | 2007-07-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100494051C (en) | Technology for preparing fine calcium phosphate using phosphor-gypsum backwater and its wash liquid | |
| CN102021329B (en) | Method for extracting tungsten from scheelite and producing high-quality calcined gypsum | |
| CN102534187B (en) | Method for treating pyrite cinder by combining acidic leaching with alkaline dissolving | |
| CN100519425C (en) | Process of extracting vanadium pentoxide from coal gangue | |
| CN102674278B (en) | Method for pre-treating phosphorus rock by titanium dioxide waste acid | |
| CN104944400A (en) | Technology for preparing iron phosphate through hydrolytic method | |
| CN109292744B (en) | Method for producing wet-process phosphoric acid and α semi-hydrated phosphogypsum from medium-grade phosphate ore | |
| CN103693670B (en) | Production method of calcium sulphate dehydrate and production device thereof | |
| CN103073034B (en) | Method for removing magnesium from ultralow-quality phosphate rock and producing magnesium hydroxide | |
| CN101434386A (en) | Method for producing fine phosphate by using dilute acid to decompose middle and low grade phosphate ore using | |
| CN109399596A (en) | Method for preparing battery-grade iron phosphate by using formed foil wastewater and iron phosphate prepared by method | |
| CN112941632A (en) | Method for preparing calcium sulfate hemihydrate crystal whisker by purifying phosphogypsum under normal pressure | |
| CN112299386A (en) | Method for removing sulfate radical in wet-process dilute phosphoric acid by using phosphate slurry | |
| CN103572058B (en) | A kind of method of enrichment rare earth rare elements and the white gypsum of preparation from sulfate process titanium dioxide waste liquid | |
| CN105384157A (en) | Technology for producing phosphoric acid through half-hydrate-dihydrate method | |
| CN104876198A (en) | Sodium fluosilicate production-phosphorite demagging combined treatment method | |
| CN104591110B (en) | A kind of concentrated wet-process phosphoric acid prepares the method for low sulfur-bearing dalcium biphosphate | |
| CN101318643A (en) | Sulphur-calcium conserving method for preparing feedstuff level hydrogen phosphate with phosphoric acid and wet-process | |
| CN111732086A (en) | Process for preparing phosphoric acid and co-producing high-purity gypsum by semi-water-dihydrate method | |
| CN104401951B (en) | The nitrogen phosphorus magnesium compound fertilizer and its production method of a kind of use high-magnesium-phosphorus ore stone production | |
| CN103539092A (en) | Preparation and applications of wet-process strong phosphoric acid desulfurizing agent | |
| CN114314540A (en) | Method for producing magnesium hydrogen phosphate by using phosphate tailings | |
| CN114477121A (en) | Production of battery-grade iron phosphate from iron-containing waste residues | |
| CN113149717A (en) | Method for extracting phosphorus from flotation tailings | |
| CN103803517A (en) | Method for producing byproduct low-silicon ardealite by using high-silicon phosphorite |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090603 Termination date: 20181221 |