CA1213734A - Process for stabilizing unstable pellets of pulverulent mineral materials - Google Patents
Process for stabilizing unstable pellets of pulverulent mineral materialsInfo
- Publication number
- CA1213734A CA1213734A CA000423321A CA423321A CA1213734A CA 1213734 A CA1213734 A CA 1213734A CA 000423321 A CA000423321 A CA 000423321A CA 423321 A CA423321 A CA 423321A CA 1213734 A CA1213734 A CA 1213734A
- Authority
- CA
- Canada
- Prior art keywords
- pellets
- water
- coating
- liquid
- pelletizing
- 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
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05B—PHOSPHATIC FERTILISERS
- C05B19/00—Granulation or pelletisation of phosphatic fertilisers, other than slag
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05G—MIXTURES OF FERTILISERS COVERED INDIVIDUALLY BY DIFFERENT SUBCLASSES OF CLASS C05; MIXTURES OF ONE OR MORE FERTILISERS WITH MATERIALS NOT HAVING A SPECIFIC FERTILISING ACTIVITY, e.g. PESTICIDES, SOIL-CONDITIONERS, WETTING AGENTS; FERTILISERS CHARACTERISED BY THEIR FORM
- C05G5/00—Fertilisers characterised by their form
- C05G5/30—Layered or coated, e.g. dust-preventing coatings
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/14—Agglomerating; Briquetting; Binding; Granulating
- C22B1/24—Binding; Briquetting ; Granulating
- C22B1/2413—Binding; Briquetting ; Granulating enduration of pellets
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Pest Control & Pesticides (AREA)
- Manufacturing & Machinery (AREA)
- Geology (AREA)
- Geochemistry & Mineralogy (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Fertilizers (AREA)
- Glanulating (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Process for stabilizing pellets of pulverulent mineral materials, for example, iron ores, dolomite, carbonate or phosphate salts for agriculture and the building trade or the like, which are unstable because of redrying, hygroscopicity or reaction with the atmosphere. After they are formed by the well-known buildup granulating process with addition of pelletizing liquid, the pellets are provided with a coating of a mineral material, which is insoluble or only slightly soluble in water. The coating can be applied by dusting the pellets especially with the oxide of a metal of the second main group and subgroup, the oxide being in the form of a dry powder, and hydroxylating by means of water or by spraying an agent in liquid, dissolved or dispersed form, which forms an insoluble or slightly water-soluble compound by reaction with the pellet material.
Process for stabilizing pellets of pulverulent mineral materials, for example, iron ores, dolomite, carbonate or phosphate salts for agriculture and the building trade or the like, which are unstable because of redrying, hygroscopicity or reaction with the atmosphere. After they are formed by the well-known buildup granulating process with addition of pelletizing liquid, the pellets are provided with a coating of a mineral material, which is insoluble or only slightly soluble in water. The coating can be applied by dusting the pellets especially with the oxide of a metal of the second main group and subgroup, the oxide being in the form of a dry powder, and hydroxylating by means of water or by spraying an agent in liquid, dissolved or dispersed form, which forms an insoluble or slightly water-soluble compound by reaction with the pellet material.
Description
~2~.3~34 The invention relates to a process for stabilizing pellets of pulverulen-t, granular or powdery mineral materials, for example, ores, dolomite, carbonate or phosphate salts for the chemical industry, the glass or ceramics industry, agri-culture and the building trade or the like, which are unstable after being agglomerated, due to redrying, hygroscopicity or reaction with -the atmosphere.
Large amounts of pulverulent, granular or powdery materials turn up in industry as raw materials or as scrap. For various reasons, the storage, transport and further processing of these materials in the existing form create considerable difficulties. These ma-terials include dusts from gas purifica-tion plants, cement dusts, and other similar dusts, which are formed during loading, transporting and dumping and therefore represent losses and a considerable contamination of the environment. They also include hygroscopic materials, such as, mineral fertilizers and building materials which, depending on the degree of -their hygroscopicity ~ 3734 and on their water-bonding capability, sometime become lumpy.
Often, in the case of the more hygroscopic materials, they may dissolve and actually become useless for transporting and for further possible processiny. Also, included in this group are materials which react chemically with oxygen or other com-ponents of the air and undergo a change in their material com-position during prolonged storage, which may also make them useless for further processing. Finally, these materials in-clude those, for example, smeltable ores, which are obtained, to a considerable extent, as dusts or finely divided materials.
These can only be processed further, or are preferably processed further, in vertical kilns, however, only or at least preferably in the form of larger pieces or aggregates.
Depending on the nature of the problem, various measures are taken in practice to counteract the above-noted disadvantages. On the whole, however, these measures are very expensive and sometimes do not satisfactorily solve the prob-lems. For example, hygroscopic materials, and those which react wi-th components or the atmosphere are stored and trans-ported in laminated bags. This results in considerable expenditures for packaging and transporting, in comparison to the usual method oE transporting dust or grain materials by belt or pipe conveyors. Also, the results are not completely satisfactory since the contents of the opened package, which ~213734 are not used immediately, are once again~exposed to air and therefore of moisture which is undesirable. Storage and transport in sheet metal containers, which can be permanently locked, is prohibitive for cost reasons.
The manufacture of nitrate-containing fertiliæers with higher acid contents for the purpose of avoiding ammonia losses in mineral fertilizers also does not lead to a satis-factory result. The oxides of nitrogen, which are formed in these mineral fertilizers represent a loss of nutrient.
~dditionally, they are extremely injurious to health and form corrosive compounds which disintegrate the packaging material ater a short time.
The agglomeration of these materials by compacting and pelletizing with a pelletizing liquid, usually water, also does not lead to a satisfactory result. This is because with hygroscopic and/or materials which react chemically with the atmosphere, such properties have not been eliminated. While these disadvantages do not exist for a large portion of the other materials referred to, such as, ores, coal dust, and most of the dustwaste, these materials are still not amenable to compaction pelletizing. This is because, after being pelletized, the pelletizing liquid escapes into the atomsphere and the pellets disintegrate into the original dust form under the sllghtest compressive stress.
~3~3~
SUMMARY OF THE INVENTION
I have discovered a process for making stable pellets for materials which are not normally amenable to the formation of permenent huildup agglomerates. In this connectiorl "build-up agglomerates" are understood to be those granulates which are formed from grain or dust material by a mixing or rolling mo-tion of the material in the absence of or wit.h the addition of a liquid phase as a granulating liquid. The present process is effective irrespective of the consistency of -the material to be processed. More particularly, the process of the present in-vention comprises granulating the finely grained or dust-like material using known procedures with the addition of a pelletiz-ing liquid. Thereaf-ter, the pellets formed are coated wi-th a mineral ma-terial which is insoluble or sligh-tly soluble in water selected from the hydroxides of metals of the second main group and sub-group of the Periodic System.
I'he invention provides a process for pelletizing materials whi.ch are amenable to agglomeration with a pelletiz-ing liquid but do no-t Eorm a stable agglomerate. This is due to either subsequen-t drying, the subsequent absorption of water because of their hydroscopicity, or chemical reactions with substances contained in the surrounding atmosphere. This I
.; ~-, . i ~2~L3739~
~an result in rapid changes in consistency and des-truction of the agglomerates. With the present invention, access of mois-tures or other components of the atmosphere to the pellet material is reliably prevented by coating the surface of the pellets or granulates formed with a layer of material, which is insoluble or slightly soluble in water. Consequently, not only the physlcal properties of the pellet, especially its strength, but also, its chemical stability are permenen-tly secured.
Material which satisfies the above conditions can be used is selected from hydroxides of metals of the second main group and subgroup of the periodic system which are parti-cularly advantageous. On the one hand, these hydroxides are also mineral materails which cause no interfering reactions in most processing procedures and can even be used to advan-tage.
On the other, they can be applied -to the pellets in an extre-mely simple manner in that the material, which is first of all to be agglomerated, is prepared with an addition of pellet.iz-ing liquid, and the coating material is applied as the dry metal oxide and hydroxylated by surface moisture or the addi-tion of water.
In the case of the above-described embodiment of the inventive process, the selection of coating material depends on the nature of the pellet material, as well as on its fur-ther use.
~L373~
For e~ample, calcium hydroxide (Ca(OH)2) can be regarded as a preferred coating material, which can also be used to advantage for mineral materials in most areas of application, as in agriculture for neutralizing acidic soils, in the building trade as a binder, and in metallurgical smelting processes as a base material for slag formation~
In a further embodiment of the inventive process, coating can also be accomplished by spraying an agent in liquid, dissolved, or dispersed form, which reacts with the pellet material to form a compound, which is insoluble or slightly soluble in water. This forms a protective sheath in which prevents the diffusion of moisture. Depending on the pellet material and the nature of the further processing, dilute acid or alkali, organic solvents, such as, gasoline, benzene, methanol, ethanol, carbon tetrachloride, paraffin or the like can be used as the agent. Depending on the particular case, the agent, which reacts with the pellet material, can be added in an amount so that there is only partial conversion of the pelletized material during the reaction. An example of the application of this embodiment of the process is the pelletizing of natural phosphates, for example, phosphorite and apatite, which are used in agriculture, or the pelletizing of dolomite (calcium magnesium carbonate). In these cases, coating is advantageously accomplished by spraying dilute ~2~;~73~
sulfuric acid on the pellets or by using dilute sulfuric acid directly as the pelletizing llquid in the final phase of the pelletizing process. The amount of sulfuric acid added is such that the tertiary phosphate is converted only to the calcium hydrogen phosphate (CaHPO4), anhydrite (CaSO4xH2O) being formed at the same time. The sheath formed in this manner, consists only of calcium hydrogen phosphate, which is soluble in mineral acids, and the insoluble anhydrite. Thus, although the access of moisture to the core of the pellet and the diffusion of the moisture to the atmosphere are prevented, the grain can never-theless be solubilized because of the solubility of the calcium hydrogen phosphate in the mineral acids of the soil.
The coating process is advantageously carried out in a plough share mixer at a drum circumferential speed of 0.120 to 0.180 and, preferably, of 0.165 m/sec. and at an operating temperature of 30, the temperature increase during the bonding phase being limited to a maximum of 10 by controlling the addition of li~uid. In this procedure, the amount of bonding binder, ~or example, of CaO or CaSO4, added to l mole of water per mole of substance, is 2 to 5 weight percent and preferably 2 to 3 weight percent, based on the total weight of finished pellets.
~LZ~373~
The following examples illustrate the invention.
EXAMPLE l Dolocate, a mixture of dolomite and calcium carbonate (40.0 kg) is weighed into a pelletizing plow share mixer of 300 L capacity and, after addition of 7.0 kg of water as the pelletizing liquid, is processed into pellets. After a mixing time of 15-20 minutes, 3.0 kg of quick lime are added and mixed intensively with the pellets until there no longer i.s an increase in temperature. Hydroxylation according to ; 10 the reaction CaO + H2O = Ca(OH~2 is then finished and durable, solid, storable and transportable pellets are obtained for use as fertilizer or in the fermentation industry.
Calcium phosphate (50 kg) and 11.25 kg of water as pelletizing liquid are weighed into a pelletizing plough share mixer of 300 L capacity and processed into pellets. Now 2.75 kg of concentrated sulfuric acid (98.0-99.5 weight percent) are added and dlstributed unformly over the surface of the pellets by mixing at 50-60C. The formation of the sheath proceeds on the surface according to the reaction Ca3(PO4)2 +
H2SO4 = CaSO4 ~ 2CaHPO4 and then CaSO4 + H2O = CaSO4 x H2O.
lZ~L373~
The resulting pellets are mechanically solid, stable, storable, as well as trar.sportable and are suitable for the normal practical use.
Large amounts of pulverulent, granular or powdery materials turn up in industry as raw materials or as scrap. For various reasons, the storage, transport and further processing of these materials in the existing form create considerable difficulties. These ma-terials include dusts from gas purifica-tion plants, cement dusts, and other similar dusts, which are formed during loading, transporting and dumping and therefore represent losses and a considerable contamination of the environment. They also include hygroscopic materials, such as, mineral fertilizers and building materials which, depending on the degree of -their hygroscopicity ~ 3734 and on their water-bonding capability, sometime become lumpy.
Often, in the case of the more hygroscopic materials, they may dissolve and actually become useless for transporting and for further possible processiny. Also, included in this group are materials which react chemically with oxygen or other com-ponents of the air and undergo a change in their material com-position during prolonged storage, which may also make them useless for further processing. Finally, these materials in-clude those, for example, smeltable ores, which are obtained, to a considerable extent, as dusts or finely divided materials.
These can only be processed further, or are preferably processed further, in vertical kilns, however, only or at least preferably in the form of larger pieces or aggregates.
Depending on the nature of the problem, various measures are taken in practice to counteract the above-noted disadvantages. On the whole, however, these measures are very expensive and sometimes do not satisfactorily solve the prob-lems. For example, hygroscopic materials, and those which react wi-th components or the atmosphere are stored and trans-ported in laminated bags. This results in considerable expenditures for packaging and transporting, in comparison to the usual method oE transporting dust or grain materials by belt or pipe conveyors. Also, the results are not completely satisfactory since the contents of the opened package, which ~213734 are not used immediately, are once again~exposed to air and therefore of moisture which is undesirable. Storage and transport in sheet metal containers, which can be permanently locked, is prohibitive for cost reasons.
The manufacture of nitrate-containing fertiliæers with higher acid contents for the purpose of avoiding ammonia losses in mineral fertilizers also does not lead to a satis-factory result. The oxides of nitrogen, which are formed in these mineral fertilizers represent a loss of nutrient.
~dditionally, they are extremely injurious to health and form corrosive compounds which disintegrate the packaging material ater a short time.
The agglomeration of these materials by compacting and pelletizing with a pelletizing liquid, usually water, also does not lead to a satisfactory result. This is because with hygroscopic and/or materials which react chemically with the atmosphere, such properties have not been eliminated. While these disadvantages do not exist for a large portion of the other materials referred to, such as, ores, coal dust, and most of the dustwaste, these materials are still not amenable to compaction pelletizing. This is because, after being pelletized, the pelletizing liquid escapes into the atomsphere and the pellets disintegrate into the original dust form under the sllghtest compressive stress.
~3~3~
SUMMARY OF THE INVENTION
I have discovered a process for making stable pellets for materials which are not normally amenable to the formation of permenent huildup agglomerates. In this connectiorl "build-up agglomerates" are understood to be those granulates which are formed from grain or dust material by a mixing or rolling mo-tion of the material in the absence of or wit.h the addition of a liquid phase as a granulating liquid. The present process is effective irrespective of the consistency of -the material to be processed. More particularly, the process of the present in-vention comprises granulating the finely grained or dust-like material using known procedures with the addition of a pelletiz-ing liquid. Thereaf-ter, the pellets formed are coated wi-th a mineral ma-terial which is insoluble or sligh-tly soluble in water selected from the hydroxides of metals of the second main group and sub-group of the Periodic System.
I'he invention provides a process for pelletizing materials whi.ch are amenable to agglomeration with a pelletiz-ing liquid but do no-t Eorm a stable agglomerate. This is due to either subsequen-t drying, the subsequent absorption of water because of their hydroscopicity, or chemical reactions with substances contained in the surrounding atmosphere. This I
.; ~-, . i ~2~L3739~
~an result in rapid changes in consistency and des-truction of the agglomerates. With the present invention, access of mois-tures or other components of the atmosphere to the pellet material is reliably prevented by coating the surface of the pellets or granulates formed with a layer of material, which is insoluble or slightly soluble in water. Consequently, not only the physlcal properties of the pellet, especially its strength, but also, its chemical stability are permenen-tly secured.
Material which satisfies the above conditions can be used is selected from hydroxides of metals of the second main group and subgroup of the periodic system which are parti-cularly advantageous. On the one hand, these hydroxides are also mineral materails which cause no interfering reactions in most processing procedures and can even be used to advan-tage.
On the other, they can be applied -to the pellets in an extre-mely simple manner in that the material, which is first of all to be agglomerated, is prepared with an addition of pellet.iz-ing liquid, and the coating material is applied as the dry metal oxide and hydroxylated by surface moisture or the addi-tion of water.
In the case of the above-described embodiment of the inventive process, the selection of coating material depends on the nature of the pellet material, as well as on its fur-ther use.
~L373~
For e~ample, calcium hydroxide (Ca(OH)2) can be regarded as a preferred coating material, which can also be used to advantage for mineral materials in most areas of application, as in agriculture for neutralizing acidic soils, in the building trade as a binder, and in metallurgical smelting processes as a base material for slag formation~
In a further embodiment of the inventive process, coating can also be accomplished by spraying an agent in liquid, dissolved, or dispersed form, which reacts with the pellet material to form a compound, which is insoluble or slightly soluble in water. This forms a protective sheath in which prevents the diffusion of moisture. Depending on the pellet material and the nature of the further processing, dilute acid or alkali, organic solvents, such as, gasoline, benzene, methanol, ethanol, carbon tetrachloride, paraffin or the like can be used as the agent. Depending on the particular case, the agent, which reacts with the pellet material, can be added in an amount so that there is only partial conversion of the pelletized material during the reaction. An example of the application of this embodiment of the process is the pelletizing of natural phosphates, for example, phosphorite and apatite, which are used in agriculture, or the pelletizing of dolomite (calcium magnesium carbonate). In these cases, coating is advantageously accomplished by spraying dilute ~2~;~73~
sulfuric acid on the pellets or by using dilute sulfuric acid directly as the pelletizing llquid in the final phase of the pelletizing process. The amount of sulfuric acid added is such that the tertiary phosphate is converted only to the calcium hydrogen phosphate (CaHPO4), anhydrite (CaSO4xH2O) being formed at the same time. The sheath formed in this manner, consists only of calcium hydrogen phosphate, which is soluble in mineral acids, and the insoluble anhydrite. Thus, although the access of moisture to the core of the pellet and the diffusion of the moisture to the atmosphere are prevented, the grain can never-theless be solubilized because of the solubility of the calcium hydrogen phosphate in the mineral acids of the soil.
The coating process is advantageously carried out in a plough share mixer at a drum circumferential speed of 0.120 to 0.180 and, preferably, of 0.165 m/sec. and at an operating temperature of 30, the temperature increase during the bonding phase being limited to a maximum of 10 by controlling the addition of li~uid. In this procedure, the amount of bonding binder, ~or example, of CaO or CaSO4, added to l mole of water per mole of substance, is 2 to 5 weight percent and preferably 2 to 3 weight percent, based on the total weight of finished pellets.
~LZ~373~
The following examples illustrate the invention.
EXAMPLE l Dolocate, a mixture of dolomite and calcium carbonate (40.0 kg) is weighed into a pelletizing plow share mixer of 300 L capacity and, after addition of 7.0 kg of water as the pelletizing liquid, is processed into pellets. After a mixing time of 15-20 minutes, 3.0 kg of quick lime are added and mixed intensively with the pellets until there no longer i.s an increase in temperature. Hydroxylation according to ; 10 the reaction CaO + H2O = Ca(OH~2 is then finished and durable, solid, storable and transportable pellets are obtained for use as fertilizer or in the fermentation industry.
Calcium phosphate (50 kg) and 11.25 kg of water as pelletizing liquid are weighed into a pelletizing plough share mixer of 300 L capacity and processed into pellets. Now 2.75 kg of concentrated sulfuric acid (98.0-99.5 weight percent) are added and dlstributed unformly over the surface of the pellets by mixing at 50-60C. The formation of the sheath proceeds on the surface according to the reaction Ca3(PO4)2 +
H2SO4 = CaSO4 ~ 2CaHPO4 and then CaSO4 + H2O = CaSO4 x H2O.
lZ~L373~
The resulting pellets are mechanically solid, stable, storable, as well as trar.sportable and are suitable for the normal practical use.
Claims (14)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a process for making pellets from pulverulent mineral materials, wherein the pulverulent material is pelle-tized by buildup granulation with a pelletizing liquid, the improvement comprises stabilizing the pellets by coating them with a mineral material which is insoluble or slightly soluble in water and selected from the group consisting of the hydr-oxides of metals of the second main group and sub-group of the Periodic Table.
2. A process of claim 1, in which the coating material is carbon hydroxide.
3. The process of claim 1, wherein the pulverulent material is pelletized using water as the pelletizing liquid and the pellets are coated by applying a dry metal oxide thereto which is hydroxylated by water absorption from the pellet.
4. The process of claim 3, wherein the pulverulent material is pelletized using water as the pelletizing liquid and the pellets are coated by applying a dry metal oxide thereto which is hydroxylated by the addition of water.
5. The process of claim 3, wherein the dry metal oxide is applied by rolling or dusting.
6. The process of claim 4, wherein the dry metal oxide is applied by rolling or dusting.
7. The process of claim 1, wherein the coating is carried out by spraying an agent in liquid form onto the pellets which forms an insoluble or slightly water-soluble compound by reaction with the pellet material to form a pro-tective sheath which prevents the diffusion of moisture.
8. The process of claim 7, wherein the agent is selected from the group consisting of dilute acids, alkaline solutions, and organic solvents.
9. The process of claim 7, wherein the agent is an organic solvent selected from the group consisting of gasoline, benzene, methanol, ethanol, carbon tetrachloride and paraffin.
10. The process of claim 7, wherein the agent is added in an amount so that there is a partial chemical con-version of the pellet material during the reaction which does not change the properties of the pellet material.
11. The process of claim 1, wherein the coating is carried out in a plough share mixer at a drum circumferencial speed of 0.120 to 0.180 m/sec. and an operating temperature of 30°C.
12. The process of claim 11, wherein the drum speed is 0.165 m/sec.
13. The process of claim 11, wherein there is an increase in temperature during the coating and the increase is limited to a maximum of 10°C by controlling the addition of liquid to the mixer.
14. The process of claim 1, wherein the mineral coating material is CaO or CaSO4, water is the pelletizing liquid and one mole of water is added per mole of coating material and the amount of coating material is 2 to 5 weight percent based on the total amount of finished pellets.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3209618.6 | 1982-03-17 | ||
| DE19823209618 DE3209618A1 (en) | 1982-03-17 | 1982-03-17 | METHOD FOR STABILIZING UNSTABLE PELLETS MADE OF POWDERED MINERAL MATERIALS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1213734A true CA1213734A (en) | 1986-11-12 |
Family
ID=6158446
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000423321A Expired CA1213734A (en) | 1982-03-17 | 1983-03-10 | Process for stabilizing unstable pellets of pulverulent mineral materials |
Country Status (11)
| Country | Link |
|---|---|
| BE (1) | BE896167A (en) |
| CA (1) | CA1213734A (en) |
| DD (1) | DD207735A5 (en) |
| DE (1) | DE3209618A1 (en) |
| DK (1) | DK44883A (en) |
| FR (1) | FR2523481A1 (en) |
| GB (1) | GB2117748B (en) |
| IT (1) | IT1212713B (en) |
| LU (1) | LU84693A1 (en) |
| NL (1) | NL8300918A (en) |
| SE (1) | SE8301316L (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT407402B (en) * | 1999-04-22 | 2001-03-26 | Voest Alpine Ind Anlagen | METHOD FOR PRODUCING APPLICABLE MATERIAL FOR A DIRECT REDUCTION PROCESS |
| CN102203014B (en) * | 2008-09-18 | 2015-01-07 | 莱茵石灰有限公司 | Manufacture of a material on the basis of calcium- and/or magnesium carbonate having a reduced decrepitation tendency |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE645223C (en) * | 1930-10-28 | 1937-05-25 | I G Farbenindustrie Akt Ges | Process for the production of non-baking fertilizers |
| GB389508A (en) * | 1931-09-17 | 1933-03-17 | Alfred John Prince | Improvements in the production of fertilisers |
| GB559482A (en) * | 1942-06-09 | 1944-02-22 | Sturtevant Eng Co Ltd | Improvements relating to the manufacture of granular superphosphatic fertilisers |
| GB818615A (en) * | 1957-06-03 | 1959-08-19 | Illinois Clay Products Co | Method of strengthening iron ore agglomerates |
| CH433552A (en) * | 1960-12-22 | 1967-04-15 | Titan Gmbh | Water-wettable rutile titanium dioxide pigment and process for its manufacture |
| GB1032724A (en) * | 1963-06-04 | 1966-06-15 | Kalk Chemische Fabrik Gmbh | Mixtures of granular or pulverulent components and finely divided phosphates |
| US3480387A (en) * | 1966-11-15 | 1969-11-25 | Central Glass Co Ltd | Method for producing gypsum pellets |
| CA851655A (en) * | 1967-03-06 | 1970-09-15 | A. Bell James | Beneficiation of nickel-containing lateritic ores |
| GB1168106A (en) * | 1967-08-30 | 1969-10-22 | English Clays Lovering Pochin | Improvements in or relating to Granular Materials containing Anti-Caking Powders |
| GB1302931A (en) * | 1969-02-03 | 1973-01-10 | ||
| BE783003A (en) * | 1972-05-04 | 1972-11-06 | Solvay | SODIUM CHLORITE GRANULES WITH IMPROVED STABILITY. |
| US3975182A (en) * | 1973-08-09 | 1976-08-17 | United States Steel Corporation | Pellets useful in shaft furnace direct reduction and method of making same |
| JPS54143799A (en) * | 1978-04-28 | 1979-11-09 | Kao Corp | Stabilizing method for sodium percarbonate |
| JPS5839203B2 (en) * | 1979-05-31 | 1983-08-29 | 株式会社神戸製鋼所 | Slag forming agent and its manufacturing method |
-
1982
- 1982-03-17 DE DE19823209618 patent/DE3209618A1/en not_active Withdrawn
-
1983
- 1983-02-03 DK DK44883A patent/DK44883A/en not_active Application Discontinuation
- 1983-03-09 DD DD83248657A patent/DD207735A5/en unknown
- 1983-03-10 IT IT8320005A patent/IT1212713B/en active
- 1983-03-10 SE SE8301316A patent/SE8301316L/en not_active Application Discontinuation
- 1983-03-10 CA CA000423321A patent/CA1213734A/en not_active Expired
- 1983-03-14 NL NL8300918A patent/NL8300918A/en not_active Application Discontinuation
- 1983-03-15 LU LU84693A patent/LU84693A1/en unknown
- 1983-03-16 FR FR8304289A patent/FR2523481A1/en not_active Withdrawn
- 1983-03-16 BE BE2/60049A patent/BE896167A/en not_active IP Right Cessation
- 1983-03-16 GB GB08307210A patent/GB2117748B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| IT8320005A0 (en) | 1983-03-10 |
| DE3209618A1 (en) | 1983-09-22 |
| LU84693A1 (en) | 1983-09-08 |
| GB8307210D0 (en) | 1983-04-20 |
| GB2117748B (en) | 1986-01-08 |
| IT1212713B (en) | 1989-11-30 |
| BE896167A (en) | 1983-07-18 |
| SE8301316L (en) | 1983-09-18 |
| GB2117748A (en) | 1983-10-19 |
| DK44883A (en) | 1983-09-18 |
| FR2523481A1 (en) | 1983-09-23 |
| SE8301316D0 (en) | 1983-03-10 |
| DK44883D0 (en) | 1983-02-03 |
| DD207735A5 (en) | 1984-03-14 |
| NL8300918A (en) | 1983-10-17 |
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