CN102275959A - Process for producing high-purity basic magnesium carbonate from dolomite - Google Patents
Process for producing high-purity basic magnesium carbonate from dolomite Download PDFInfo
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- CN102275959A CN102275959A CN2011101999601A CN201110199960A CN102275959A CN 102275959 A CN102275959 A CN 102275959A CN 2011101999601 A CN2011101999601 A CN 2011101999601A CN 201110199960 A CN201110199960 A CN 201110199960A CN 102275959 A CN102275959 A CN 102275959A
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- magnesium
- basic carbonate
- rhombspar
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Abstract
The invention discloses a process for producing high-purity basic magnesium carbonate from dolomite, which adopts a carbonization method and uses dolomite as a raw material. The method comprises the following steps: grinding, calcining, digesting the calcined dolomite, filtering, carbonizing magnesium emulsion, pyrolyzing a heavy magnesium solution, and drying to obtain basic magnesium carbonate. The carbonization process of the magnesium emulsion is as follows: after the magnesium emulsion is cooled, carbon dioxide is introduced; when the pH value reaches 7.5-9.5, oxalic acid or soluble oxalate is added to ensure that the concentration of oxalate groups in the system is 0.001-0.01mol/L; and after the system is mixed evenly, carbonization is performed continuously until the pH value is 6.5-7.0, filtration is performed, the filtrate is the refined heavy magnesium solution, and the residue is light calcium carbonate. By adding oxalic acid in the digesting process, the technical problem of the dolomite carbonization method that calcium and magnesium are difficult to separate thoroughly can be solved. The process is simple, is easy to control and has high magnesium oxide extraction rate and high product purity.
Description
Technical field
The present invention relates to the processing method of mineral processing and utilization, be specially the processing method that rhombspar prepares high pure alkali formula magnesiumcarbonate.
Background technology
The magnesium basic carbonate molecular formula is xMgCO
3YMg (OH)
2ZH
2O, the x value is 3 ~ 5, and y is approximately 1, and the z value is 3～7.As a kind of important inorganic chemical product, magnesium basic carbonate also can be used as the additive or the modifying agent of rubber, medicine, insulating material, food and various Chemicals except the raw material as preparation highly-purity magnesite, magnesium salts series product, and Application Areas is extensive.The processing method of producing magnesium basic carbonate at present mainly is a carborization, and main raw material has magnesite, serpentine and rhombspar.Though the magnesite reserves are abundant, country develops restricted conservation policy to it, and the serpentine reserves are limited and its development and use are limited by the region.China's rhombspar resource distribution is extensive, retained reserve is 82.2 hundred million tons, the various places that spread all over the country, the place of production, Liaoning, the Inner Mongol, Shanxi, Henan, Hebei, Jiangsu, Anhui, Hunan, Hubei, Sichuan, Chongqing, Fujian, zhejiang and other places all have large-scale rhombspar mineral deposit.Therefore, with the rhombspar be having a extensive future of raw material production magnesium basic carbonate.
The key issue that the rhombspar carborization is produced magnesium basic carbonate is to solve the very difficult thoroughly separation of calcium magnesium.At present, improving one's methods of rhombspar carbonized bodies system mainly contained the secondary carbonization, the carbonization of pressurizeing, is added with organic additive.The secondary carborization is that the calcic heavy magnesium water pyrolysis after the carbonization is obtained carrying out the carbonization second time behind the calcic magnesiumcarbonate, preparing high-purity magnesium basic carbonate through pyrolysis again, but energy consumption increases.When carbonization, increase carbonization pressure during the pressurization carbonization, increase CO in the carbonization system
2Concentration makes more magnesium enter liquid phase, filter after purer basic carbonate magnesium products is prepared in pyrolysis, but the pressurization carbonization is higher to equipment requirements.Being added with organic additive, is to add organic additive (mainly being organic amine) when carbonization, enters liquid phase after organic additive and the magnesium complexing, the content of MgO in the raising heavy magnesium water, but organic additive costs an arm and a leg, and increased production cost.Chinese invention patent application number 200810053967.0 discloses a kind of dolomite sea water bittern and has produced Magnesium Carbonate Light 41-45 and method of magnesium oxide, wherein relate to the technology of preparing of magnesium basic carbonate, it is characterized in that obtaining heavy magnesium water, add NaOH, KOH, Mg (OH) at last carrying out carbonization again behind rhombspar Digestive system and the sea water bittern prepared in reaction magnesium hydroxide
2Prepare magnesium basic carbonate Deng alkaline matter.Seawater in this technology and bittern need carry out complicated impurity removal process, and need add alkaline matter when separating out magnesium basic carbonate, and raw materials cost increases.Chinese invention patent application number 201010149986.0 discloses a kind of method of utilizing rhombspar to produce high-purity magnesium oxide, wherein relate to the technology of preparing of magnesium basic carbonate, its principal character is to add to contain mineral alkali and water-soluble high-molecular material in rhombspar carbonization system, as polyvinyl alcohol, methylcellulose gum etc., carbonization is to pH=7, and pyrolysis obtains magnesium basic carbonate after filtering.This process using mineral alkali and expensive high molecular polymer, not only cause filtration difficulty but also cost to increase, be difficult to promote.
Summary of the invention
Be difficult to thorough isolating problem in order to solve the calcium magnesium that exists in the existing carborization production, the invention provides a kind of rhombspar and produce the processing method of high-purity magnesium basic carbonate, add oxalic acid or solubility oxalate during by carbonization, improve the productive rate of rhombspar carborization production magnesium basic carbonate, solved the very difficult thorough isolating technical problem of calcium magnesium in the rhombspar carborization simultaneously.
Technical scheme of the present invention is: a kind of rhombspar is produced the processing method of high-purity magnesium basic carbonate, adopt carborization, with the rhombspar is raw material, through pulverizing, calcining, forge white digestion, filter, the magnesium latex emulsion carbonization, the heavy magnesium water pyrolysis, oven dry obtains magnesium basic carbonate, wherein, the magnesium latex emulsion carbonization is after treating the magnesium latex emulsion cooling, feed carbonic acid gas, when the pH value reaches 7.5～9.5, add oxalic acid or solubility oxalate, the concentration that makes system medium-height grass acid group is 0.001～0.01mol/L, after the system thorough mixing was even, continuing carbonization was 6.5～7.0 to pH, filtration, filtrate is refining heavy magnesium water, and residue is a light calcium carbonate.
The flow velocity of carbonic acid gas is 0.5L/min～1L/min.
Described solubility oxalate be in sodium oxalate, potassium oxalate, the ammonium oxalate any one or arbitrarily several arbitrarily than mixture.
When forging white digestion, water is 30 ~ 70:1 with forging white mass ratio, and the digestion temperature is 50 ~ 80 ℃, and digestion time is 0.5 ~ 4h.
When forging white digestion, water is 40 ~ 50:1 with forging white mass ratio, and the digestion temperature is 60 ~ 70 ℃, and digestion time is 1 ~ 3h.
Described heavy magnesium water pyrolysis, be with heavy magnesium water at 90 ~ 100 ℃ of following pyrolysis 1 ~ 4h, obtain the basic carbonate magnesium precipitate, obtain the magnesium basic carbonate filter cake after the filtration, filtrate is used to digest operation after adding water once more.
Produce the magnesium basic carbonate that the processing method of high-purity magnesium basic carbonate obtains with described rhombspar, by mass percentage, CaO content is lower than 0.2%, Fe content is lower than 0.003%, MgO content is higher than 41%.
Beneficial effect:1, with the rhombspar be the high-purity magnesium basic carbonate of raw material production, abundant raw material, production cost are low; 2, produce high-purity magnesium basic carbonate with carborization, its technology is simple, be easy to suitability for industrialized production; 3, adding concentration in the rhombspar carbonization system is oxalic acid or the solubility oxalate of 0.001 ~ 0.01mol/L, utilization is under identical pH value, the Magnesium hydrogen carbonate that generates is solvable and lime carbonate and caoxalate are insoluble, solve calcium magnesium and be difficult to thorough isolating problem, 4, its finished product purity height, the productive rate height.
Description of drawings
Fig. 1 is that the X-ray diffraction of raw material rhombspar is analyzed collection of illustrative plates;
Fig. 2 is that the X-ray diffraction of high-purity magnesium basic carbonate product of embodiment 1 is analyzed collection of illustrative plates.
Embodiment
Further set forth the present invention by the following examples, these embodiment are only presented for purposes of illustration, do not limit the scope of the invention.The experimental technique of unreceipted actual conditions in the following example is usually according to normal condition.
A kind of rhombspar is produced the processing method of high-purity magnesium basic carbonate, specifically comprises following step:
(1) rhombspar fragmentation: rhombspar is carried out Mechanical Crushing to 1cm ~ 10cm, best big 2cm～5cm; Can use crusher to carry out fragmentation;
(2) dolomite calcination: the rhombspar of fragmentation is calcined 0.5 ~ 5h down at 850 ℃ ~ 1100 ℃ obtain forging white; Optimum calcinating temperature is 900 ℃～1000 ℃, and calcination time is 1h～3h.
(3) forge white digestion: will forge white is that 30:1 ~ 70:1 adds water according to water with forging white mass ratio, and the best is the ratio of 40 ~ 50:1, and adding thermal control digestion temperature is 50 ℃ ~ 80 ℃, fully stirs 0.5h ~ 4h; Best digestion temperature is 60 ℃ ~ 70 ℃, and digestion time is 1h ~ 3h.
(4) Digestive system filters: the filtrate of above-mentioned digestion is crossed 60 mesh sieves, remove the residue that can not fully digest, obtain thinner magnesium latex emulsion;
(5) magnesium latex emulsion carbonization: after the magnesium latex emulsion cooling, feed carbonic acid gas, keeping the flow velocity of carbonic acid gas is 0.5L/min ~ 1L/min.And the pH of tracking and testing magnesium latex emulsion, when pH reached 7.5 ~ 9.5, more preferably pH was 8 ~ 9 o'clock, added oxalic acid or solubility oxalate in system, the concentration that makes the oxalate in the system is 0.001 ~ 0.01mol/L, fully shake up the back continue carbonization to pH be 6.5 ~ 7.0; Corresponding chemical equation is as follows:
CO
2+Ca(OH)
2=CaCO
3↓
Mg(OH)
2?+2CO
2=Mg(HCO
3)
2
CaCO
3+CO
2+H
2O=Ca(HCO
3)
2
Ca(HCO
3)
2?+?C
2O
4 2-?=?CaC
2O
4?↓+?2HCO
3 -
(6) magnesium latex emulsion filters: the emulsion after the carbonization, to filter, and residual residue is a light calcium carbonate, filtrate is refining heavy magnesium water;
(7) heavy magnesium water pyrolysis: heavy magnesium water is more preferred from 95 ℃ ~ 100 ℃ at 90 ~ 100 ℃ of following pyrolysis 1 ~ 4h, and pyrolysis 2h ~ 3h obtains the basic carbonate magnesium precipitate, obtains the magnesium basic carbonate filter cake after the filtration, and its filtrate is salts solution, continue to add water be used to digest new forge white;
(8) magnesium basic carbonate oven dry: the magnesium basic carbonate filter cake after pyrolysis is filtered, 100 ℃ ~ 220 ℃ down baking 1h ~ 5h obtain lily magnesium basic carbonate, by mass percentage, CaO content is lower than 0.2%, Fe content is lower than 0.003%, MgO content is higher than 41%.Better bake out temperature is 120 ℃ ~ 180 ℃, and drying time is 1h ~ 3h.
Embodiment 1: the chemical constitution of rhombspar is a MgO content 20.96%, and CaO content 30.06% is crushed to 2 ~ 5cm.Calcine 3h down at 900 ℃, must forge white.To forge white according to water: forging white mass ratio is the 50:1 mixing, and control digestion temperature is 60 ℃, and insulation digestion 1h gets emulsion.Emulsion is crossed 60 mesh sieves, obtains smart magnesium latex emulsion.Feed CO after being cooled to room temperature
2, CO
2Flow velocity is 0.5L/min, and tracking and testing carbonization system pH value.When carbonized bodies is pH=8.5, add ammonium oxalate, the concentration that makes system medium-height grass acid group is 0.002mol/L, continues carbonization to pH=6.5, stops carbonization.With the system solid-liquid separation after the carbonization, solid phase is a light calcium carbonate, and liquid phase is a heavy magnesium water.The gained heavy magnesium water is at 95 ℃ of following pyrolysis 2h, cooling back solid-liquid separation, solid phase is dried by the fire 2h down at 150 ℃ and is magnesium basic carbonate, analyzing its chemical constitution is: MgO content 41.7%, CaO content is 0.12%, Fe content is 0.001%, and X-ray diffraction is analyzed collection of illustrative plates and is shown as pure magnesium basic carbonate, and structural formula is 4MgCO
3Mg (OH)
24H
2O.
Embodiment 2: the chemical constitution of rhombspar is a MgO content 20.96%, and CaO content 30.06% is crushed to 2 ~ 5cm.Calcine 2.5h down at 950 ℃, must forge white.To forge white according to water: forging white mass ratio is that 40:1 mixes, and is heated with stirring to 70 ℃, and insulation digestion 1.5h gets emulsion.Emulsion is crossed 60 mesh sieves, obtains smart magnesium latex emulsion.Feed CO after being cooled to room temperature
2, CO
2Flow velocity is 0.8L/min, and tracking and testing carbonization system pH.When carbonized bodies is pH=9.0, add oxalic acid, the concentration that makes system medium-height grass acid group is 0.005mol/L, continues carbonization to pH=6.8, stops carbonization.With the system solid-liquid separation after the carbonization, solid phase is a light calcium carbonate, and liquid phase is a heavy magnesium water.The gained heavy magnesium water is at 100 ℃ of following pyrolysis 2h, cooling back solid-liquid separation, solid phase is dried by the fire 1h down at 180 ℃ and is magnesium basic carbonate, analyzing its chemical constitution is: MgO content 42.0%, CaO content is 0.08%, Fe content is 0.002%, and X-ray diffraction is analyzed collection of illustrative plates and is shown as pure magnesium basic carbonate, and structural formula is 4MgCO
3Mg (OH)
24H
2O.
Table 1 is the reaction conditions tabulation that embodiment 3～embodiment 5 is adopted.
Table 1
A=globule size in the table 1; The b=calcining temperature; The c=calcination time; D=water with forge white mass ratio; E=hot digestion temperature; The f=digestion time; G=filters sieve aperture; H=CO
2Flow velocity; Carbonization system pH when i=adds oxalic acid; J=oxalate concentration; K=terminal point pH; The l=pyrolysis temperature; The m=pyrolysis time; The n=bake out temperature; The o=drying time.Except the listed condition of table 1, all the other contents are with embodiment 1.
Table 2 is purity, foreign matter contents of high-purity magnesium basic carbonate of preparing of embodiment 3～embodiment 5 and whether meets the evaluation of HG/T 2959-2000 " industrial hydration magnesium basic carbonate " to the premium grads technical requirements.By purity listed in embodiment 1, embodiment 2 and the table 2 and foreign matter content data as can be seen, constant product quality of the present invention, meet the premium grads technical requirements of HG/T 2959-2010 " industrial hydration magnesium basic carbonate " fully, also meet the technical requirements of HG2790-1996 " foodstuff additive magnesium basic carbonate " simultaneously.
Table 2
| Embodiment | 3 | 4 | 5 |
| MgO | 41.5% | 41.8% | 41.0% |
| CaO | 0.13% | 0.10% | 0.18% |
| Fe | 0.002% | 0.003% | 0.003% |
| Estimate | Meet | Meet | Meet |
Claims (7)
1. processing method that rhombspar is produced high-purity magnesium basic carbonate, adopt carborization, with the rhombspar is raw material, through pulverizing, calcining, forge white digestion, filter, the magnesium latex emulsion carbonization, the heavy magnesium water pyrolysis, oven dry obtains magnesium basic carbonate, it is characterized in that, the magnesium latex emulsion carbonization is after treating the magnesium latex emulsion cooling, feed carbonic acid gas, when the pH value reaches 7.5～9.5, add oxalic acid or solubility oxalate, the concentration that makes system medium-height grass acid group is 0.001～0.01mol/L, after the system thorough mixing was even, continuing carbonization was 6.5～7.0 to pH, filtration, filtrate is refining heavy magnesium water, and residue is a light calcium carbonate.
2. rhombspar as claimed in claim 1 is produced the processing method of high-purity magnesium basic carbonate, it is characterized in that, the flow velocity of carbonic acid gas is 0.5L/min～1L/min.
3. rhombspar as claimed in claim 1 is produced the processing method of high-purity magnesium basic carbonate, it is characterized in that, described solubility oxalate be in sodium oxalate, potassium oxalate, the ammonium oxalate any one or arbitrarily several arbitrarily than mixture.
4. rhombspar as claimed in claim 1 is produced the processing method of high-purity magnesium basic carbonate, it is characterized in that, when forging white digestion, water is 30 ~ 70:1 with forging white mass ratio, and the digestion temperature is 50 ~ 80 ℃, and digestion time is 0.5 ~ 4h.
5. rhombspar as claimed in claim 4 is produced the processing method of high-purity magnesium basic carbonate, it is characterized in that, when forging white digestion, water is 40 ~ 50:1 with forging white mass ratio, and the digestion temperature is 60 ~ 70 ℃, and digestion time is 1 ~ 3h.
6. rhombspar as claimed in claim 1 is produced the processing method of high-purity magnesium basic carbonate, it is characterized in that, described heavy magnesium water pyrolysis, be at 90 ~ 100 ℃ of following pyrolysis 1 ~ 4h with heavy magnesium water, obtain the basic carbonate magnesium precipitate, obtain the magnesium basic carbonate filter cake after the filtration, filtrate is used to digest operation after adding water once more.
7. the magnesium basic carbonate that obtains of the processing method of producing high-purity magnesium basic carbonate with the arbitrary described rhombspar of claim 1 ~ 6 is characterized in that, by mass percentage, CaO content is lower than 0.2%, Fe content is lower than 0.003%, MgO content is higher than 41%.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103922369A (en) * | 2014-03-22 | 2014-07-16 | 彭振超 | Process of producing magnesium carbonate-series products by dolomite lime smoke gas desulfurization carbon-drop power generation |
| CN105271320A (en) * | 2015-11-23 | 2016-01-27 | 中国科学院青海盐湖研究所 | Preparation method of morphology-controlled magnesium oxide nanocrystalline |
| CN110446685A (en) * | 2017-01-25 | 2019-11-12 | 南洋理工大学 | The concrete mix of reactive magnesium oxide cements based on enhancing |
| CN111422891A (en) * | 2020-05-14 | 2020-07-17 | 沈阳工业大学 | Method for comprehensive utilization of magnesite |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5285999A (en) * | 1976-01-08 | 1977-07-16 | Vaw Ver Aluminium Werke Ag | Process for preparing calcium or magnesium carbonates |
| CN1031687A (en) * | 1987-09-03 | 1989-03-15 | 平乐县化工厂 | A kind of is the novel method of raw material production Magnesium Carbonate Light 41-45 with the rhombspar |
| CN101935059A (en) * | 2010-09-29 | 2011-01-05 | 北京化工大学 | Clean preparation method for basic magnesium carbonate |
-
2011
- 2011-07-18 CN CN 201110199960 patent/CN102275959B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5285999A (en) * | 1976-01-08 | 1977-07-16 | Vaw Ver Aluminium Werke Ag | Process for preparing calcium or magnesium carbonates |
| CN1031687A (en) * | 1987-09-03 | 1989-03-15 | 平乐县化工厂 | A kind of is the novel method of raw material production Magnesium Carbonate Light 41-45 with the rhombspar |
| CN101935059A (en) * | 2010-09-29 | 2011-01-05 | 北京化工大学 | Clean preparation method for basic magnesium carbonate |
Non-Patent Citations (1)
| Title |
|---|
| 毛小浩 等: "氯化镁制备碱式碳酸镁研究", 《山西冶金》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103922369A (en) * | 2014-03-22 | 2014-07-16 | 彭振超 | Process of producing magnesium carbonate-series products by dolomite lime smoke gas desulfurization carbon-drop power generation |
| CN105271320A (en) * | 2015-11-23 | 2016-01-27 | 中国科学院青海盐湖研究所 | Preparation method of morphology-controlled magnesium oxide nanocrystalline |
| CN110446685A (en) * | 2017-01-25 | 2019-11-12 | 南洋理工大学 | The concrete mix of reactive magnesium oxide cements based on enhancing |
| CN110446685B (en) * | 2017-01-25 | 2022-09-06 | 南洋理工大学 | Concrete mixture based on reinforced reactive magnesia cement |
| CN111422891A (en) * | 2020-05-14 | 2020-07-17 | 沈阳工业大学 | Method for comprehensive utilization of magnesite |
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