GB2320494A - Treatment of slag by size screening - Google Patents
Treatment of slag by size screening Download PDFInfo
- Publication number
- GB2320494A GB2320494A GB9726803A GB9726803A GB2320494A GB 2320494 A GB2320494 A GB 2320494A GB 9726803 A GB9726803 A GB 9726803A GB 9726803 A GB9726803 A GB 9726803A GB 2320494 A GB2320494 A GB 2320494A
- Authority
- GB
- United Kingdom
- Prior art keywords
- fraction
- size
- slag
- stainless steel
- screening
- 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.)
- Withdrawn
Links
- 239000002893 slag Substances 0.000 title claims abstract description 51
- 238000012216 screening Methods 0.000 title claims abstract description 21
- 229910001220 stainless steel Inorganic materials 0.000 claims abstract description 39
- 239000010935 stainless steel Substances 0.000 claims abstract description 39
- 239000003516 soil conditioner Substances 0.000 claims abstract description 26
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 24
- 239000006227 byproduct Substances 0.000 claims abstract description 15
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 12
- 238000004519 manufacturing process Methods 0.000 claims abstract description 10
- 238000000034 method Methods 0.000 claims description 25
- 238000011084 recovery Methods 0.000 claims description 8
- 229910000831 Steel Inorganic materials 0.000 claims description 6
- 239000000428 dust Substances 0.000 claims description 6
- 239000010959 steel Substances 0.000 claims description 6
- 238000012545 processing Methods 0.000 claims description 5
- 239000000047 product Substances 0.000 claims description 5
- 238000000498 ball milling Methods 0.000 claims description 4
- 238000001035 drying Methods 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 239000010426 asphalt Substances 0.000 claims description 2
- 230000003472 neutralizing effect Effects 0.000 claims description 2
- 239000000463 material Substances 0.000 description 7
- 238000007792 addition Methods 0.000 description 5
- 239000011651 chromium Substances 0.000 description 5
- 239000002689 soil Substances 0.000 description 5
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 3
- 229910052804 chromium Inorganic materials 0.000 description 3
- 239000011777 magnesium Substances 0.000 description 3
- 210000003625 skull Anatomy 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 239000005864 Sulphur Substances 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- 238000012958 reprocessing Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229940072033 potash Drugs 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Substances [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 1
- 235000015320 potassium carbonate Nutrition 0.000 description 1
- 239000003923 scrap metal Substances 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 231100000701 toxic element Toxicity 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Classifications
-
- 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
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
- C22B7/04—Working-up slag
-
- 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
- B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
- B03B9/00—General arrangement of separating plant, e.g. flow sheets
- B03B9/04—General arrangement of separating plant, e.g. flow sheets specially adapted for furnace residues, smeltings, or foundry slags
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
- B07B9/00—Combinations of apparatus for screening or sifting or for separating solids from solids using gas currents; General arrangement of plant, e.g. flow sheets
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K17/00—Soil-conditioning materials or soil-stabilising materials
- C09K17/02—Soil-conditioning materials or soil-stabilising materials containing inorganic compounds only
- C09K17/04—Soil-conditioning materials or soil-stabilising materials containing inorganic compounds only applied in a physical form other than a solution or a grout, e.g. as granules or gases
-
- 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
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
- C22B7/005—Separation by a physical processing technique only, e.g. by mechanical breaking
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Materials Engineering (AREA)
- Geology (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Environmental & Geological Engineering (AREA)
- Inorganic Chemistry (AREA)
- Soil Sciences (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
Slag from a stainless steel manufacturing process is subjected to a first size screening to divide it into a first larger size fraction and a second smaller size fraction, the second fraction is subjected to second size screening to divide it into third and fourth fractions, the fourth fraction being of less than 3 mm in size and the third fraction being of greater size than the fourth fraction, wherein the fourth fraction is recovered as a usable by product. The fourth fraction, containing up to 5% by weight of nickel, may particularly be used as a soil conditioner. Stainless steel scrap may be recovered from the third and fourth fractions.
Description
UTILISATION OF SLAG
This invention relates to the utilisation of slag and is particularly concerned to improve the utilisation of slag from stainless steel production.
Stainless steel slag essentially comprises as much as about 75% by weight of very fine, so-called "falling" slag. Currently, the slag from, for example, a commercial AOD stainless steel plant is tipped molten into a "lagoon". A certain amount of stainless steel skull separates from the slag and can be recycled in the steel manufacturing process. The slag when cold is subjected to screening in a recovery process which separates the slag into, for example, + 50 mm, from 9 mm to 50 mm and -9 mm fractions, the latter containing all naturally arising fines including the falling slag, some small stainless steel scrap and some small-sized nonfalling slag.
The large size, e.g. +50 size, material can be returned for reprocessing to extract unrecovered scrap steel. It also may be used to repair and elevate road sites.
The intermediate size, e.g. -50 mm to +9 mm size, material comprises the non-falling slag and is useful as an aggregate for asphalt manufacture. Further stainless steel scrap may also be recovered at this stage and re-used.
No commercial use has, however, been found for the small size, e.g.
-9 mm, material. It is land-filled at considerable expense and has, therefore, been a recurring waste problem since the production of stainless steel began.
It is an object of the present invention to provide a method of treating this hitherto waste product and to convert it to a useful by-product of the stainless steel making process.
Accordingly, in one aspect the invention provides a method of treating slag from a stainless steel manufacturing process in which the slag is subjected to a first size screening to divide it into a first larger size fraction and a second smaller size fraction, the second fraction is subjected to second size screening to divide it into third and fourth fractions, the fourth fraction being of less than 3 mm in size and the third fraction being of greater size than the fourth fraction, wherein the fourth fraction is recovered as a usable by product.
Preferably the second fraction is below 9 mm in size and the fourth fraction is below 1 mm in size.
The fourth fraction should contain no more than 5% by weight of nickel.
Conveniently, the first size screening may be adapted to correspond to the current recycling of the stainless steel slag described above. Thus the first size screening may divide the slag into an above 50 mm fraction, a fraction between 9 mm and 50 mm and a fraction below 9 mm. Thus in this embodiment the fraction below 9 mm is the second fraction as defined in the method of the invention and the first fraction as defined in the method of the invention actually comprises two parts, a first part above 50 mm and a second part between 9 mm and 50 mm. These two parts may then be recycled for further use as described above.
It will be appreciated, however, that although these size limits for the various parts and fractions may be suitable for incorporation into processes with existing machinery and sieve sizes, the size limit may be varied widely provided that the final usable by product, i.e. the fourth fraction, is restricted to the above-defined size and nickel content.
The third fraction, i.e. the above 1 mm fraction in the preferred embodiment, may be subjected to a ball mill operation to separate out fines and then the coarser product of the ball milling may be screened for further recovery of fine stainless steel scrap.
We have surprisingly found that the fourth fraction, i.e. especially (but not exclusively) below 1 mm size, can be used as a soil conditioner, particularly for acid soils. However, the fourth fraction should not be ground to too fine a dust or it will be less suitable for use as a soil conditioner as its fineness will cause problems of handling.
Above 3 mm size, use as a soil conditioner is less effective as spreading equipment, for example, for liming is geared for use with -3 mm material. Larger particles also take too long to break down in the soil.
Accordingly, in another aspect the invention provides a soil conditioner comprising a stainless steel slag by-product, the by-product being a fraction obtained by screening the slag of a stainless steel processing plant to a size below 3 mm and containing up to 5% by weight of nickel.
In the method of the invention the stainless steel slag will normally be wetted for handling purposes so that the second fraction obtained from the first screening step will be in a damp condition and is, therefore, dried before the second screening to produce the third and fourth fractions. A dust collection step is preferably included between the drying stage and the screening stage and we have also found that fines collected at this dust collection step also have useful properties as a soil conditioner.
Accordingly the soil conditioner of the present invention may also include these fines added to the fourth fraction by-product. Since these fines are a relatively small proportion by weight of the recovered soil conditioner by-product, the resulting mixture does not suffer from the above-mentioned problems of a too fine product.
Preferably, moisture is added to the soil conditioner by-product to render it more easy to handle. For example, from 2 to 3% by weight of water may be found suitable.
We have found that the soil conditioner of the invention is a very good substitute for lime. For example, representative samples of the fourth fraction of the present invention have been found to have a liming potential
NV (Neutralising Value) of about 44% in comparison with a typical NV of about 56% for almost pure calcium carbonate. The fines collected between the drying step and second screening of the invention have been found typically to have a liming potential of over 53%.
The soil conditioner of the invention also contains small but useful amounts of sulphur and magnesium.
Moreover, the soil conditioner of the invention has low levels of potentially toxic elements (PTE's). Table 1 below lists the constituents of a typical soil conditioner - fourth fraction of the invention, which was screened to below 1 mm.
TABLE 1
PTE Lab Result Content Addition to soil Maximum per
g or kg/t at St/ha missible PTE
(kg/ha) addition kg/ha/year# Sulphur 0.101% 0.99 kg/t 4.95 Potassium 0.02% 0.20 kg/t Potash (K20) - 0.24kg/t 1.18
Magnesium (Mg) 3.67% 35.9kg/t 180
Lead 3.36 mg/kg 3.3 g/t 0.016 15
Nickel 1130 mg/kg 1.107 kg/t 5.53 3
Zinc 30.67mg/kg 30.04g/t 0.15 15
Cadmium < 0.1 mg/kg nd - 0.15
Chromium (Cr) 2260 mg/kg 2.213 kg/t 11.07 15
Extractable
Cr 1.89 mg/l 2.51*g/t 0.012
Copper 36.9 mg/kg 36.14g/t 0.18 7.5
* Assuming density of 1.33 t/m3.
# Limit averaged over 10 years.
From Table 1 it can be seen that in this particular sample all the PTE constituents were within the maximum permissible additions per year except for nickel. However, as the maximum permissible additions per year are averaged over a ten year period this sample could be applied to a particular plot of land every other year without exceeding the permissible level for nickel.
It will be appreciated that liming of agricultural soils is not carried out every year and may only be done, for example, once in two, three, five or even 10 years. A limit of 5% by weight of nickel in the conditioner of the invention, therefore, would enable its use at 5 tons/ha only once in 10 years to stay within the permitted 30 kg/ha/10 years. If a soil conditioner is required for use every five, three or two years, for example, then the maximum nickel content must be reduced accordingly, i.e. to 2.5%, 1.5% and 1% by weight of the soil conditioner.
These PTE results are very significant when it is realised that it was well known that stainless steel slag of below 9 mm size has significant levels of chromium which preclude its use in agriculture. Thus prior to the present invention it was not possible to use any portion of the many thousands of tons of stainless steel slag as a soil conditioner and hence the expensive need to use landfill sites to dispose of the fractions that are too small for uses such as in roadstone plants.
The invention is further described by way of example only with reference to the accompanying drawings in which:
Figure 1 shows schematically a typical current commercial slag reprocessing and handling cycle for stainless steel manufacturing in solid lines with additional steps of the present invention shown in broken lines; and
Figure 2 shows the steps of one embodiment of the present invention in greater detail.
In Figure 1 slag from a stainless steel melt shop is tipped into slag pots at stage 1. It is transported in the slag pots and tipped into a lagoon at stage 2. Solid steel skulls separating from the slag in lagoon 2 are segregated at stage 2A, cleaned and lanced at stage 2B and returned to the stainless steel manufacturer at M.
Slag while still hot is dug from the lagoon after the skull segregation and placed in a storage building at stage 3. It is cooled with water at stage 4 and transported at stage 5 to a processing plant, stage 6.
In the processing plant, stainless steel scrap is recovered by hand picking and magnetic recovery at stage 6A and by use of a tipping screen at stage 6B. The metal recovered at 6A and 6B is returned to the stainless steel manufacturer at M.
The remaining slag in the processing plant is screened to produce above 9 mm slag, which is delivered to a roadstone plant at stage 7, and below 9 mm slag which is transported to a landfill site at stage 8. The slag delivered to the roadstone plant at stage 7 is crushed to obtain a -3 mm material for use in bituminous macadams and a metal portion of above 3 mm which is recovered and returned at stage 7A to the steel manufacturer at M.
The below 9 mm slag is then treated according to the method of the present invention. It is screened to divide it into a below 1 mm fraction and an above 1 mm fraction. The below 1 mm fraction is recovered at stage 9 for use as a soil conditioner. The above 1 mm fraction is subjected to a ball milling process at stage 10 which results in recovery of further stainless steel scrap of greater than 1 mm size at stage 10A, which is returned to the stainless steel manufacturer at M, and crushed slag of below 1 mm which is sent to a landfill site at stage 11. Clearly the landfill sites at stages 8 and 11 may be the same. Indeed stage 11 is a usefil addition to the overall process because some slag fines are always required for the landfill sites to stabilise fumes and secondary dusts from the steelworks.
It will also be noted that the ball milling at stage 10 results in recovery of further stainless steel scrap from below 9 mm slag which is normally lost to a landfill site. Under conventional commercial production of stainless steel, it has not proved to be an economic proposition to recover the stainless steel scrap from the proportion of the slag that has found no other use and is landfilled. However, the present invention by providing a useflil saleable by product from this fraction of the slag, leads to the further benefits of enabling scrap metal recovery at this stage. The amount of stainless steel recovered at stage 10 may be, for example, between 1 and 2 per cent by weight of the second fraction, or higher.
The embodiment shown schematically in Figure 2 starts after stage 6 of Figure 1. A feed of damp slag from a stage equivalent to stage 5 of
Figure 1 is dried in a rotary drier at stage A. The moisture loss at this stage is of the order of 7 to 8% by weight, for example.
Dust collection, stage B, is carried out between the drying stage A and a subsequent screening stage C. Here the dried slag is screened to a smaller than 1 mm fraction, i.e. the fourth fraction of the above-defined process, and a larger than 1 mm fraction, the third fraction as defined in the process.
The fourth fraction from stage 21 is usable as a soil conditioner and may comprise, for example, about 50 per cent by weight of the original damp slag fed to the drier. It may be mixed, if desired, with the fines collected from stage B, which may add, for example another 10 to 15% by weight of the damp slag fed to the drier.
The third fraction, i.e. above 1 mm, is processed through a ball mill at stage D to separate fines from coarser material. The coarser material may then be screened again at stage E and, as shown in this embodiment, is divided into It1200 micron, -1200 to +800 micron and -800 micron fractions. The +1200 micron fraction is essentially stainless steel and may be returned to the manufacturer for recycling.
The dusts of the -200 to +800 fraction and of the -800 fraction contain smaller amounts of stainless steel so that further extraction may be warranted. Moreover, it should be noted that we have found that these fractions contain relatively high amounts of PTE's, especially chromium and, hence are unsuitable for use as a soil conditioner.
It can be seen, therefore, that the present invention provides a number of benefits.
Firstly, it provides a new product in the form of soil improver recovered from stainless steel scrap.
Secondly, it eliminates the need to landfill many thousands of tons of slag per annum that previously had no commercial end use.
Thirdly, it renders economic the recovery and re-use of stainless steel scrap from the slag fractions that have hitherto been landfilled.
Overall, the invention enables the stainless steel slag to be treated and segregated in such a manner that the overall distribution of PTE's is significantly altered so that they are effectively reduced in the by-product intended as a soil conditioner and concentrated in the fractions to be recycled to the steel manufacturer or landfilled.
Claims (19)
1. A method of treating slag from a stainless steel manufacturing process in which the slag is subjected to a first size screening to divide it into a first larger size fraction and a second smaller size fraction, the second fraction is subjected to second size screening to divide it into third and fourth fractions, the fourth fraction being of less than 3 mm in size and the third fraction being of greater size than the fourth fraction, wherein the fourth fraction is recovered as a usable by product.
2. A method according to Claim 1, in which the second fraction is below 9 mm in size.
3. A method according to Claim 1 or 2, in which the fourth fraction is below 1 mm in size.
4. A method according to Claim 1, 2 or 3, in which the fourth fraction contains no more than 5% by weight of nickel.
5. A method according to any preceding claim, in which the first size screening divides the slag into an above 50 mm fraction, a fraction between 9 mm and 50 mm and a fraction below 9 mm, wherein the above 50 mm fraction and the between 9 mm and 50 mm fraction comprise the first fraction and the below 9 mm fraction comprises the second fraction.
6. A method according to Claim 5, in which the above 50 mm fraction is reprocessed to extract unrecovered scrap steel.
7. A method according to Claim 5 or 6, in which the fraction between 9 mm and 50 mm is used as an aggregate for asphalt manufacture.
8. A method according to any preceding claim, in which the third fraction is subjected to a ball mill operation to separate out fines and the remaining coarser product of the ball milling is screened for further recovery of stainless steel scrap.
9. A method according to any preceding claim, in which the stainless steel slag is wetted prior to the first screening and the second smaller size fraction is then dried before the second screening.
10. A method according to Claim 9, in which a dust collection step is provided between the drying and the second screening stage.
11. A method according to Claim 10, in which the fines collected at the dust collection stage are added to the fourth fraction.
12. A method according to any preceding claim, in which from 2 to 3% by weight of water is added to the fourth fraction to render it a more easily handleable by product.
13. A method according to Claim 1, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
14. A soil conditioner made by the method of any preceding claim.
15. A soil conditioner comprising a stainless steel slag by product, the by product being a fraction obtained by screening the slag of a stainless steel processing plant to a size below 3 mm and containing up to 5% by weight of nickel.
16. A soil conditioner according to Claim 15, which contains up to 2.5% by weight of nickel.
17. A soil conditioner according to Claim 15 or 16, in which has been screened to below 1 mm.
18. A soil conditioner according to Claim 15, 16 or 17 which contains from 2 to 3% by weight of water.
19. A soil conditioner according to any one of Claims 15 to 18, which has a liming potential (neutralising value) of over 53%.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9626531A GB9626531D0 (en) | 1996-12-20 | 1996-12-20 | Utilisation of slag |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9726803D0 GB9726803D0 (en) | 1998-02-18 |
| GB2320494A true GB2320494A (en) | 1998-06-24 |
Family
ID=10804782
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9626531A Pending GB9626531D0 (en) | 1996-12-20 | 1996-12-20 | Utilisation of slag |
| GB9726803A Withdrawn GB2320494A (en) | 1996-12-20 | 1997-12-18 | Treatment of slag by size screening |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9626531A Pending GB9626531D0 (en) | 1996-12-20 | 1996-12-20 | Utilisation of slag |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB9626531D0 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1055647A3 (en) * | 1996-10-17 | 2002-01-23 | Trading and Recycling Company Sint Truiden | Process for processing stainless steel slags |
| RU2205883C2 (en) * | 2000-07-04 | 2003-06-10 | Промисинг Фьюче Корпорэйшн | Method of processing waste dump slag of nickel process |
| WO2008145758A1 (en) * | 2007-05-31 | 2008-12-04 | Recmix Belgium | Process for preparing a filler for asphalt or concrete starting from a slag material |
| CN108947744A (en) * | 2018-10-15 | 2018-12-07 | 中国农业科学院衡阳红壤实验站 | Conditioner for relieving soil acidification of rice field |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2971703A (en) * | 1958-06-04 | 1961-02-14 | Frank E Rath | Process for cleaning and recovering scrap metal from slag and the like |
| US3165268A (en) * | 1963-01-08 | 1965-01-12 | Harsco Corp | Method and apparatus for processing ferrous slag |
| GB2232907A (en) * | 1989-06-05 | 1991-01-02 | Delaporte D Haille Susana | Separation of metal from slag from furnaces |
| US4985060A (en) * | 1985-07-04 | 1991-01-15 | Saken Corporation | Soil conditioners |
| FR2666098A1 (en) * | 1990-08-27 | 1992-02-28 | Tratamiento Transformacion Mat | Plant for recovering raw materials from special steel slags |
| US5417738A (en) * | 1993-06-03 | 1995-05-23 | Ok-Soo Oh | Method for recovering metals included in the slag generated from steel making process |
| US5427607A (en) * | 1994-11-07 | 1995-06-27 | Her Majesty The Queen In Right Of Canada As Represented By The Minister Of Energy, Mines And Resources | Process for the recovery of metallic iron from slags and other residues |
-
1996
- 1996-12-20 GB GB9626531A patent/GB9626531D0/en active Pending
-
1997
- 1997-12-18 GB GB9726803A patent/GB2320494A/en not_active Withdrawn
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2971703A (en) * | 1958-06-04 | 1961-02-14 | Frank E Rath | Process for cleaning and recovering scrap metal from slag and the like |
| US3165268A (en) * | 1963-01-08 | 1965-01-12 | Harsco Corp | Method and apparatus for processing ferrous slag |
| US4985060A (en) * | 1985-07-04 | 1991-01-15 | Saken Corporation | Soil conditioners |
| GB2232907A (en) * | 1989-06-05 | 1991-01-02 | Delaporte D Haille Susana | Separation of metal from slag from furnaces |
| FR2666098A1 (en) * | 1990-08-27 | 1992-02-28 | Tratamiento Transformacion Mat | Plant for recovering raw materials from special steel slags |
| US5417738A (en) * | 1993-06-03 | 1995-05-23 | Ok-Soo Oh | Method for recovering metals included in the slag generated from steel making process |
| US5427607A (en) * | 1994-11-07 | 1995-06-27 | Her Majesty The Queen In Right Of Canada As Represented By The Minister Of Energy, Mines And Resources | Process for the recovery of metallic iron from slags and other residues |
Non-Patent Citations (1)
| Title |
|---|
| WPI Abstract Accession No. 92-134336/199217 & FR 2666098 A1 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1055647A3 (en) * | 1996-10-17 | 2002-01-23 | Trading and Recycling Company Sint Truiden | Process for processing stainless steel slags |
| RU2205883C2 (en) * | 2000-07-04 | 2003-06-10 | Промисинг Фьюче Корпорэйшн | Method of processing waste dump slag of nickel process |
| WO2008145758A1 (en) * | 2007-05-31 | 2008-12-04 | Recmix Belgium | Process for preparing a filler for asphalt or concrete starting from a slag material |
| WO2008145189A1 (en) * | 2007-05-31 | 2008-12-04 | Recmix Belgium | Process for preparing a filler for asphalt or concrete starting from a slag material |
| US8628612B2 (en) | 2007-05-31 | 2014-01-14 | Recmix Belgium | Process for preparing a filler for asphalt or concrete starting from a slag material |
| CN108947744A (en) * | 2018-10-15 | 2018-12-07 | 中国农业科学院衡阳红壤实验站 | Conditioner for relieving soil acidification of rice field |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9726803D0 (en) | 1998-02-18 |
| GB9626531D0 (en) | 1997-02-05 |
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| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |