CA2057165C - Method of improvement of the yield of electrostatic separation of salts - Google Patents
Method of improvement of the yield of electrostatic separation of saltsInfo
- Publication number
- CA2057165C CA2057165C CA 2057165 CA2057165A CA2057165C CA 2057165 C CA2057165 C CA 2057165C CA 2057165 CA2057165 CA 2057165 CA 2057165 A CA2057165 A CA 2057165A CA 2057165 C CA2057165 C CA 2057165C
- Authority
- CA
- Canada
- Prior art keywords
- process according
- added
- salt
- rock salt
- salts
- 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 - Lifetime
Links
- 238000000926 separation method Methods 0.000 title claims abstract description 4
- 238000000034 method Methods 0.000 title claims description 24
- 150000003839 salts Chemical class 0.000 title description 6
- 235000002639 sodium chloride Nutrition 0.000 claims abstract description 18
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims abstract description 13
- 239000011780 sodium chloride Substances 0.000 claims abstract description 13
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical class [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims abstract description 11
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 claims description 14
- 229910052928 kieserite Inorganic materials 0.000 claims description 12
- 239000000463 material Substances 0.000 claims description 10
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical group [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 claims description 8
- 239000001103 potassium chloride Substances 0.000 claims description 7
- 235000011164 potassium chloride Nutrition 0.000 claims description 7
- 229910052943 magnesium sulfate Inorganic materials 0.000 claims description 2
- 238000012216 screening Methods 0.000 claims description 2
- 239000002245 particle Substances 0.000 claims 3
- 239000012080 ambient air Substances 0.000 claims 1
- 239000003795 chemical substances by application Substances 0.000 claims 1
- 230000003750 conditioning effect Effects 0.000 claims 1
- 235000019341 magnesium sulphate Nutrition 0.000 claims 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 6
- 235000010755 mineral Nutrition 0.000 description 6
- 239000011707 mineral Substances 0.000 description 6
- 229910052925 anhydrite Inorganic materials 0.000 description 5
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 5
- WZISDKTXHMETKG-UHFFFAOYSA-H dimagnesium;dipotassium;trisulfate Chemical compound [Mg+2].[Mg+2].[K+].[K+].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O WZISDKTXHMETKG-UHFFFAOYSA-H 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 4
- 230000001143 conditioned effect Effects 0.000 description 3
- YGSDEFSMJLZEOE-UHFFFAOYSA-N salicylic acid Chemical compound OC(=O)C1=CC=CC=C1O YGSDEFSMJLZEOE-UHFFFAOYSA-N 0.000 description 2
- USFZMSVCRYTOJT-UHFFFAOYSA-N Ammonium acetate Chemical compound N.CC(O)=O USFZMSVCRYTOJT-UHFFFAOYSA-N 0.000 description 1
- 239000005695 Ammonium acetate Substances 0.000 description 1
- 241000282320 Panthera leo Species 0.000 description 1
- 229940043376 ammonium acetate Drugs 0.000 description 1
- 235000019257 ammonium acetate Nutrition 0.000 description 1
- 238000010420 art technique Methods 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- 230000005686 electrostatic field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000000194 fatty acid Substances 0.000 description 1
- 229930195729 fatty acid Natural products 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- FJKROLUGYXJWQN-UHFFFAOYSA-N papa-hydroxy-benzoic acid Natural products OC(=O)C1=CC=C(O)C=C1 FJKROLUGYXJWQN-UHFFFAOYSA-N 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 229960004889 salicylic acid Drugs 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C7/00—Separating solids from solids by electrostatic effect
- B03C7/003—Pretreatment of the solids prior to electrostatic separation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C7/00—Separating solids from solids by electrostatic effect
- B03C7/006—Charging without electricity supply, e.g. by tribo-electricity or pyroelectricity
Landscapes
- Drilling And Exploitation, And Mining Machines And Methods (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
During the electrostatic separation of crude potash salts, rock salt of a defined grain size is admixed in order to increase the surface charge density and to improve the product yield.
Description
2 205716~
, The in~e.,lion relates to a process for increasin~ and improvin~ the cl,ar~e durin~ the electrostatic separation of mixtures.
The elecl-Gsldlic procedure for separating fine-grained materials in free-fall separators is of ~reat technical importance, especially for processin~5 crude potash salts.
Prior to under~oin~ the actual separatin~ process, the ground-up crude potash salt is conditioned usin~ a conditionin~ a~ent, heated and equilibrated by means of air havin~ a defined relative humidity. As a result, the polasl, salt becomes selectively char~ed, positively or ne~atively 10 accordin~ to the type of conditionin~ a~ent used. Next, the crude potash salt can be separated into its component parts in an ele~;lrostalic free-fall separator. The eleclrostatic process for separatin~ crude potash salts is disc!)ssed in detail in ~Chemie, In~enieur, Technik~ 55, (1983), 39.
German Patent 16 67 814 describes the extraction of the mineral 15 kieserite and reveals the conditionin~ a~ents used. The purer the extracted materials should be, the smaller the number of forei~n salts that can be considered as opposite char~e carriers. Therefore, large quantities of the ",aterial to be extracted must recirculated.
In German Patent 11 80 331 Alundum, which consists of fused 20 aluminium oxide spheres in lump form onto which conditionin~ a~ents have been absorbed, is for example added to the material to be separated, in order to achieve improved separatin~ conditions.
The surprising discover~ has now been made that a remarkable impro~e.-,ent in the separatin~ performance can be achieved by addin~ rock 25 salt. It is preferred that this salt itself be separated out a~ain. The rock salt used has a defined ~rain size of preferably 1-4 mm and it is added to the already conditioned mixture. The surface char~e density is increased throu~h the mixin~ process, and the essQci~ted friction between the ~rains.
The added rock salt is particularly errec~ e where the product is already 30 present in enriched form, such as enriched fractions of KCI or kieserite.
Advanta~eously, the coarse NaCI fraction is separated by screenin~
after the ele~;l,ical char~e has built up, but before the material is put throu~h the eleclroslalic field; it is then recycled and re-used in order to subject further ,..atorial to the same alecl-ical char~in~ process.
B~ ~
~_ -3-The NaCI is used in an amount ranging from 5 to 50 wt.%, preferably 10-30 wt.%.
The process according to the invention is explained in further detail by the following examples. A crude potash salt containing 11.7 wt.% K20 is 5 used having the following mineral composition:
18.1 wt. % sylvite 29.1 wt. % kieserite 1.2 wt.% langbeinite 0.5 wt.% anhydrite 51.1 wt. % rock salt + miscellaneous Screen analysis of the crude salt:
> 1.0 mm = 9.5%
1.0 - 0.8 mm = 13.3%
0.8 - 0.5 mm = 16.2%
0.5 - 0.25 mm = 23.0%
0.25 - 0.16 mm = 12.4%
0.16- 0.1 mm = 10.4%
0.1 - 0.063 mm = 9.7%
<0.063 mm = 5.5%
Using an industrial scale plant, 100 t/h of crude potash salt containing 20 g/t salicylic acid 60 g/t fatty acid 100 g/t ammonium acetate are conditioned and fluidized in a fluidized bed warming installation with air having a relative humidity of 10 wt.%, and as a result the material becomes triboelectrically charged; it is then separated in a tubular free-fall separatorin an electrostatic field at a field strength of 4 KV/cm. The results obtained using the process according to the invention and the current state-of- the-art process are shown in the following examples:
2Q57~6S
~ 4 EXAMPLE 1 (state of the art) Fig. 1 describes a complete test according to the state of the art technology. A total of 75.6 t/h of material having a 14.9 wt.% content of K20 is obtained at the positively charged electrode.
The mineral analysis is as follows:
23.4 wt.% sylvite 8.8 wt.% kieserite 0.3 wt.% langbeinite 0.3 wt.% anhydrite 67.2 wt. % rock salt + miscellaneous.
The fraction at the negative pole is subsequently separated in the second separating stage as per Fig. 1, and finally, in the third separating stage, enriched kieserite is obtained in an amount of 24.4 t/h and having a content of 1.9 wt.% K20 and the following mineral composition 1 .6 wt. % sylvite 92.0 wt.% kieserite 3.9 wt.% langbeinite 1.1 wt.% anhydrite 1.4 wt.% rock salt + miscellaneous EXAMPLE 2 (process according to the invention) In the identical test based on the process according to the invention, which is shown in Fig. 2, the following results are obtained:
In separating stage 1, a residue is obtained in the amount of 74.7 t/h and having a content of 15.1 wt.% K20 and a mineral composition of 23.7 wt.% sylvite 7.7 wt.% kieserite 0.3 wt.% langbeinite 0.3 wt.% anhydrite 68 .0 wt. % rock salt + miscellaneous .
The reason for the difference between the invention and the state of the art process is that material recycled from separating stage ll is modified.
Coarse NaCI having the following screen analysis is added in an amount of 205716~5 ~_ -5-approx. 5-20 t/h to the material accumulating at the rate of approx. 50-60 t/h after separating stage 1.
Screen analysis of the coarse rock salt:
> 4.0 mm = 8.4%
, The in~e.,lion relates to a process for increasin~ and improvin~ the cl,ar~e durin~ the electrostatic separation of mixtures.
The elecl-Gsldlic procedure for separating fine-grained materials in free-fall separators is of ~reat technical importance, especially for processin~5 crude potash salts.
Prior to under~oin~ the actual separatin~ process, the ground-up crude potash salt is conditioned usin~ a conditionin~ a~ent, heated and equilibrated by means of air havin~ a defined relative humidity. As a result, the polasl, salt becomes selectively char~ed, positively or ne~atively 10 accordin~ to the type of conditionin~ a~ent used. Next, the crude potash salt can be separated into its component parts in an ele~;lrostalic free-fall separator. The eleclrostatic process for separatin~ crude potash salts is disc!)ssed in detail in ~Chemie, In~enieur, Technik~ 55, (1983), 39.
German Patent 16 67 814 describes the extraction of the mineral 15 kieserite and reveals the conditionin~ a~ents used. The purer the extracted materials should be, the smaller the number of forei~n salts that can be considered as opposite char~e carriers. Therefore, large quantities of the ",aterial to be extracted must recirculated.
In German Patent 11 80 331 Alundum, which consists of fused 20 aluminium oxide spheres in lump form onto which conditionin~ a~ents have been absorbed, is for example added to the material to be separated, in order to achieve improved separatin~ conditions.
The surprising discover~ has now been made that a remarkable impro~e.-,ent in the separatin~ performance can be achieved by addin~ rock 25 salt. It is preferred that this salt itself be separated out a~ain. The rock salt used has a defined ~rain size of preferably 1-4 mm and it is added to the already conditioned mixture. The surface char~e density is increased throu~h the mixin~ process, and the essQci~ted friction between the ~rains.
The added rock salt is particularly errec~ e where the product is already 30 present in enriched form, such as enriched fractions of KCI or kieserite.
Advanta~eously, the coarse NaCI fraction is separated by screenin~
after the ele~;l,ical char~e has built up, but before the material is put throu~h the eleclroslalic field; it is then recycled and re-used in order to subject further ,..atorial to the same alecl-ical char~in~ process.
B~ ~
~_ -3-The NaCI is used in an amount ranging from 5 to 50 wt.%, preferably 10-30 wt.%.
The process according to the invention is explained in further detail by the following examples. A crude potash salt containing 11.7 wt.% K20 is 5 used having the following mineral composition:
18.1 wt. % sylvite 29.1 wt. % kieserite 1.2 wt.% langbeinite 0.5 wt.% anhydrite 51.1 wt. % rock salt + miscellaneous Screen analysis of the crude salt:
> 1.0 mm = 9.5%
1.0 - 0.8 mm = 13.3%
0.8 - 0.5 mm = 16.2%
0.5 - 0.25 mm = 23.0%
0.25 - 0.16 mm = 12.4%
0.16- 0.1 mm = 10.4%
0.1 - 0.063 mm = 9.7%
<0.063 mm = 5.5%
Using an industrial scale plant, 100 t/h of crude potash salt containing 20 g/t salicylic acid 60 g/t fatty acid 100 g/t ammonium acetate are conditioned and fluidized in a fluidized bed warming installation with air having a relative humidity of 10 wt.%, and as a result the material becomes triboelectrically charged; it is then separated in a tubular free-fall separatorin an electrostatic field at a field strength of 4 KV/cm. The results obtained using the process according to the invention and the current state-of- the-art process are shown in the following examples:
2Q57~6S
~ 4 EXAMPLE 1 (state of the art) Fig. 1 describes a complete test according to the state of the art technology. A total of 75.6 t/h of material having a 14.9 wt.% content of K20 is obtained at the positively charged electrode.
The mineral analysis is as follows:
23.4 wt.% sylvite 8.8 wt.% kieserite 0.3 wt.% langbeinite 0.3 wt.% anhydrite 67.2 wt. % rock salt + miscellaneous.
The fraction at the negative pole is subsequently separated in the second separating stage as per Fig. 1, and finally, in the third separating stage, enriched kieserite is obtained in an amount of 24.4 t/h and having a content of 1.9 wt.% K20 and the following mineral composition 1 .6 wt. % sylvite 92.0 wt.% kieserite 3.9 wt.% langbeinite 1.1 wt.% anhydrite 1.4 wt.% rock salt + miscellaneous EXAMPLE 2 (process according to the invention) In the identical test based on the process according to the invention, which is shown in Fig. 2, the following results are obtained:
In separating stage 1, a residue is obtained in the amount of 74.7 t/h and having a content of 15.1 wt.% K20 and a mineral composition of 23.7 wt.% sylvite 7.7 wt.% kieserite 0.3 wt.% langbeinite 0.3 wt.% anhydrite 68 .0 wt. % rock salt + miscellaneous .
The reason for the difference between the invention and the state of the art process is that material recycled from separating stage ll is modified.
Coarse NaCI having the following screen analysis is added in an amount of 205716~5 ~_ -5-approx. 5-20 t/h to the material accumulating at the rate of approx. 50-60 t/h after separating stage 1.
Screen analysis of the coarse rock salt:
> 4.0 mm = 8.4%
4.0 - 3.15 mm = 14.9%
3.15- 2.0 mm = 39.9%
2.0 - 1.5 mm = 35.6%
< 1.5 mm = 1.2%
Simultaneously, the electrical charging process takes place and screening is carried out at 1.5 mm. The underflow from the screen goes to separating stage ll and the coarse fraction is re-used.
The enriched kieserite now appears in separating stage ll in an amount of 25.3 t/h containing 1.8 wt.% K2 and having the following mineral analysis:
1.5 wt.% sylvite 92.2 wt.% kieserite 3.9 wt.% langbeinite 1.1 wt.% anhydrite 1.3 wt.% rock salt + miscellaneous A comparison of the figures shows an increased amount of kieserite and thus also a higher kieserite yield.
Using the process according to the invention the MgS04 yield is 80.6 wt.% while according to the state-of-the-art technique the yield is only 77.5 wt.%-The positive effect of the process according to the invention is thus proved.
3.15- 2.0 mm = 39.9%
2.0 - 1.5 mm = 35.6%
< 1.5 mm = 1.2%
Simultaneously, the electrical charging process takes place and screening is carried out at 1.5 mm. The underflow from the screen goes to separating stage ll and the coarse fraction is re-used.
The enriched kieserite now appears in separating stage ll in an amount of 25.3 t/h containing 1.8 wt.% K2 and having the following mineral analysis:
1.5 wt.% sylvite 92.2 wt.% kieserite 3.9 wt.% langbeinite 1.1 wt.% anhydrite 1.3 wt.% rock salt + miscellaneous A comparison of the figures shows an increased amount of kieserite and thus also a higher kieserite yield.
Using the process according to the invention the MgS04 yield is 80.6 wt.% while according to the state-of-the-art technique the yield is only 77.5 wt.%-The positive effect of the process according to the invention is thus proved.
Claims (8)
1. A process for extracting useful materials from crude potash salts, wherein:
(a) the crude potash salt is ground to particles below 1.5 mm in size;
(b) a conditioning agent is added;
(c) the particles are triboelectrically charged by agitating them in ambient air adjusted to a certain temperature and relative humidity;
(d) the particles are then separated electrostatically in several stages in free-fall separators;
(e) rock salt is added and mixed with the potash salts in order to increase the surface charge density.
(a) the crude potash salt is ground to particles below 1.5 mm in size;
(b) a conditioning agent is added;
(c) the particles are triboelectrically charged by agitating them in ambient air adjusted to a certain temperature and relative humidity;
(d) the particles are then separated electrostatically in several stages in free-fall separators;
(e) rock salt is added and mixed with the potash salts in order to increase the surface charge density.
2. A process according to Claim 1 wherein the added rock salt has a defined grain size, preferably in the range 1 - 4 mm.
3. A process according to Claims 1 wherein the rock salt is added to a product fraction which has already been enriched by electrostatic separation.
4. A process according to one of Claims 1, 2 or 3 wherein, after being mixed with and brought into mutual contact with the potash salt, the rock salt is separated out again by screening and re-used by further admixing it with fresh material.
5. A process according to one of claims 1, 2 or 3 wherein the NaCI
is added in the amount of 5 to 50 wt.%, preferably 10 to 30 wt.%.
is added in the amount of 5 to 50 wt.%, preferably 10 to 30 wt.%.
6. A process according to claim 5, wherein said amount of NaCI is about 10 wt.% to about 30 wt.%.
7. A process according to one of Claims 1, 2, 3 or 6, wherein the product obtained is kieserite (= MgSO4.H2O).
8. A process according to one of Claims 1, 2, 3 or 6, wherein the product is sylvite (= potassium chloride).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19904039470 DE4039470C1 (en) | 1990-12-11 | 1990-12-11 | Useful material obtd. e.g. kieserite from potassium mineral - by milling, adding conditioning agent, adding rock salt to increase surface charge density and sepg. electrostatically |
| DEP4039470.0 | 1990-12-11 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2057165A1 CA2057165A1 (en) | 1992-06-12 |
| CA2057165C true CA2057165C (en) | 1996-07-09 |
Family
ID=6420037
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2057165 Expired - Lifetime CA2057165C (en) | 1990-12-11 | 1991-12-06 | Method of improvement of the yield of electrostatic separation of salts |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2057165C (en) |
| DE (1) | DE4039470C1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4214950C1 (en) * | 1992-05-06 | 1994-01-05 | Kali & Salz Ag | Increasing yield in electrostatic sepn. of hard salt contg. carnallite - by recycling residue from potash purificn. stage to potash sepn. from kieserite |
| DE102006036467B4 (en) | 2006-08-04 | 2008-09-18 | K + S Aktiengesellschaft | Process for the treatment of kieserite-containing ground potash salts |
| RU2369558C2 (en) * | 2007-08-07 | 2009-10-10 | ОАО "Сильвинит" | Device for processing of sylvinite-carnallite raw materials |
-
1990
- 1990-12-11 DE DE19904039470 patent/DE4039470C1/en not_active Expired - Lifetime
-
1991
- 1991-12-06 CA CA 2057165 patent/CA2057165C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE4039470C1 (en) | 1992-01-30 |
| CA2057165A1 (en) | 1992-06-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKEX | Expiry |