CA2216063C - Method for cleanup of contaminated sandy soils and recovery of hydrocarbons therefrom - Google Patents
Method for cleanup of contaminated sandy soils and recovery of hydrocarbons therefrom Download PDFInfo
- Publication number
- CA2216063C CA2216063C CA 2216063 CA2216063A CA2216063C CA 2216063 C CA2216063 C CA 2216063C CA 2216063 CA2216063 CA 2216063 CA 2216063 A CA2216063 A CA 2216063A CA 2216063 C CA2216063 C CA 2216063C
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- Canada
- Prior art keywords
- slurry
- sandy soil
- thickening
- separating
- stream
- Prior art date
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Links
- 239000002689 soil Substances 0.000 title claims abstract description 98
- 238000000034 method Methods 0.000 title claims abstract description 58
- 229930195733 hydrocarbon Natural products 0.000 title claims description 17
- 150000002430 hydrocarbons Chemical class 0.000 title claims description 17
- 238000011084 recovery Methods 0.000 title abstract description 7
- 239000002002 slurry Substances 0.000 claims abstract description 93
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 60
- 230000008719 thickening Effects 0.000 claims abstract description 25
- 150000001805 chlorine compounds Chemical class 0.000 claims abstract description 24
- 238000012958 reprocessing Methods 0.000 claims abstract description 9
- 239000013505 freshwater Substances 0.000 claims abstract description 8
- 238000010438 heat treatment Methods 0.000 claims abstract description 7
- 238000012216 screening Methods 0.000 claims abstract description 7
- 238000012545 processing Methods 0.000 claims description 15
- 239000002245 particle Substances 0.000 claims description 14
- 239000007787 solid Substances 0.000 claims description 14
- 239000004927 clay Substances 0.000 claims description 11
- 238000005406 washing Methods 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 7
- 238000013019 agitation Methods 0.000 claims description 3
- 238000004140 cleaning Methods 0.000 claims description 3
- 229910000831 Steel Inorganic materials 0.000 claims description 2
- 238000007885 magnetic separation Methods 0.000 claims description 2
- 239000010959 steel Substances 0.000 claims description 2
- 239000006185 dispersion Substances 0.000 claims 1
- 238000004062 sedimentation Methods 0.000 claims 1
- 239000000295 fuel oil Substances 0.000 abstract description 9
- 239000003921 oil Substances 0.000 abstract description 8
- 239000010426 asphalt Substances 0.000 abstract description 4
- 229910001385 heavy metal Inorganic materials 0.000 abstract description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 18
- 239000004576 sand Substances 0.000 description 15
- 239000004094 surface-active agent Substances 0.000 description 5
- 150000003839 salts Chemical class 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 230000003749 cleanliness Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- 239000004215 Carbon black (E152) Substances 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- SMWDFEZZVXVKRB-UHFFFAOYSA-N Quinoline Chemical compound N1=CC=CC2=CC=CC=C21 SMWDFEZZVXVKRB-UHFFFAOYSA-N 0.000 description 2
- 239000013543 active substance Substances 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000011707 mineral Substances 0.000 description 2
- 235000013824 polyphenols Nutrition 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- ORMHZBNNECIKOH-UHFFFAOYSA-N 4-(4-hydroxy-4-methylpentyl)cyclohex-3-ene-1-carbaldehyde Chemical compound CC(C)(O)CCCC1=CCC(C=O)CC1 ORMHZBNNECIKOH-UHFFFAOYSA-N 0.000 description 1
- 241000283690 Bos taurus Species 0.000 description 1
- 241001177068 Clerus Species 0.000 description 1
- 101100361772 Mus musculus Rptn gene Proteins 0.000 description 1
- 101100096985 Mus musculus Strc gene Proteins 0.000 description 1
- 101100206738 Mus musculus Tiam2 gene Proteins 0.000 description 1
- 101150034459 Parpbp gene Proteins 0.000 description 1
- 206010039740 Screaming Diseases 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 238000010960 commercial process Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 208000031513 cyst Diseases 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 150000002240 furans Chemical class 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
- 239000002920 hazardous waste Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000000575 pesticide Substances 0.000 description 1
- 125000005575 polycyclic aromatic hydrocarbon group Chemical group 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 238000005488 sandblasting Methods 0.000 description 1
- 235000020046 sherry Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 235000013547 stew Nutrition 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C1/00—Reclamation of contaminated soil
- B09C1/02—Extraction using liquids, e.g. washing, leaching, flotation
-
- 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
- B03B9/02—General arrangement of separating plant, e.g. flow sheets specially adapted for oil-sand, oil-chalk, oil-shales, ozokerite, bitumen, or the like
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Geology (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Soil Sciences (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
A method is provided for cleanup of the fine fraction (<= 1.0 mm) of sandy soils contaminated with heavy oil/ bitumen, chlorides and heavy metals and for recovery of heavy oil/ bitumen from aqueous slurries of these soils. The method includes the steps of screening the sandy soil, preparing hot aqueous slurry of prescreened soil, screening and heating the slurry in a slurry heater, separating oily froth and contaminated process water from the slurry of precleaned sandy soil and thickening the precleaned sandy soil in a separating/thickening vessel followed by reprocessing the thicken slurry of precleaned sandy soil. Reprocessing generates some additional quantities of residual oily froth and contaminated process water from the sandy oil which is washed with fresh water, dewatered and renders sandy soil that meets the criteria for agricultural soil in Canada.
Description
Mctt~od for Cleanup of Contaminated Sandy Soils and Recovery of Hydrocarbons Therefrom The. present invention is directed to a method for efficient cleanup of the tint tiaction ( ~l.Omm) of c;ontamin,ated sandy soils arid recovery of valuable hydrocarbons from aqueous slurries of lhe~,e soils.
Background of the Invcnt:ion Ficlld of the Invention: Commercial processes for production of heavy oil/
bitumen generate large quantities of hydrocarbon and salt contaminated soils. in view of tightening environmental regulations and laws, the disposal of such coratarrainated soils is becoming a major iiahility tier the upstream peire~leum industry. There is a need for a technology that could clean the contaminated sandy soils to required cleanliness criteria, recover the hydrocarbons during the cleaning process and accomplish that at a reasonable capital and processing vests.
Description of Yrior Art: Application of commercially available soil washing technologies (1 ) for rcmediation of heavy oil/ bitumen and salt contaminated soils either fails to meet the criteria for residual concentration of contaminants in the product soil or is associated with such high ousts that the upstream heavy oil producc;~~s/ processors are reluctant to seriously consider those teclwologies as a potential solution to their oily sand problem.
The high processing cost of effective soil wsjshint; technologies is usually associated with extensive usage of surfactants, proprietary additives, conditioners and other surface active agents.
To entrance the eiTectiveneas of surface active agents the washing processes are usually carried out at modez~ate (< Stl°C) t~:mpcratures which, in turn, requires extended residence times and may have a negative impact on capital and operating cysts. At elevated (>SO°C) temperatures the torc:cs of physical adsorption, upon which the surf"ace active agents work, are becoming too weak to compete with the vibration forces of heat, C.'.onscqucntly, the surface active agents usually Ioose their effectiveness with an increase in the temperature. However, at sufficiently high temperature the (,physical) adheaian furc~es between; floe c~~ntaminant and the soil particle should be likewise rc;duc;ui.
1t is the object of the present invention to provide a method for effective removal of heavy oil/hitumen and various salts from very !'toe soil particles (< l.Omm) by processing aqueous slurries of these particles at sul~iciently high temperatures, in a system specifically designed fbr this purpose and without the addition of surfac:e active agents.
It is another object of the present invention to provide a system for effective recovery of valuable hydrocarbons trotn the heated sherry of' very fine conttuninatcd soil particles.
These and other objects of the present invention will be apparent from the following description of the preferred embodiments and the appended claims and from practicx of the invenlic~n.
Summary The present invention provides an et~ectiv~ method For cleanup of the fine fraction (_< l.Omm) of corntaminated sandy sUll ~~nd 1'or an efficient recovery of hydrocarbons from the slurry of contaminated sandy soil processed in a system shecific;ally designed for this purpose; the method tnc:ludes the steps of screaming the sandy soil feed to :remove oversize (>25.0 nom) material, preparing hot aqueous stun°y of pre-screened sandy soil, screening the aqueous slurry to remove the ;particles larger than 1.0 mm and heating the resultant slurry to auy required temperature level of up to 99°C in a slurry heater; separating the oily tioth and process water contaminated with oil, clay and silt from the slurred of precleaned sandy soil in a scparatinglthiekening vessel and further lhic;kening the slurry of pre;clcaned sandy soil; contaclinlthe lhiclren slurry of precleaned sandy soil with hot treated pror~ess water and separating in another sepat~dtinl;/thickening vessel the residual oily fiotli and some of the contaminaicd process water from the slurry of clean sandy soil; thickening the slurry of the cleru~ :~rndy sail and dew:~tering the slurry followed by washing the sandy soil with fresh water, having temperature of up to 99°C, to generrate sandy soil containing less than lUUO ~ppm residual hydroc:rrbans, less lhan lUU ppm residual ttrtal chlorides and mewling rather criteria as required by lnterim t~anadian Environmental (duality Criteria for Con tarninated Sites (2).
The; present invention, as sumnaari~ecl above, cleans the sandy soil to a lcvc;l required for depositing thv soil at any suitably located lire without causing any environmental problems or for utilizing the soil product as a fccdstock for some industries. To clean the soil to meet required criteria, the present invent:ican does not require application of any surface active agents which is typical of prior art described under "Description of Prior Art".
Brief Description of the Drawings In the accompanying tigurfa;
Fig.l presents a process diagram ot~ a. system for cleanup of contaminated sandy soils and recovery of hydroc~u-bons, as rcduired by present invention rig. 2 presents, according io present ixivention, a slurry heater for direct stcun heating of sandy soil slurry Fig. 3 presents, according to present invention, a schematic drawing of a separating/thickening vessel for direct steam heating of sandy soil slurry and separating the slurry into oily froth, p.roeess wafer for treatme~rt and thicken slurry of sandy sail De:rcriptio~n of the Preferred Embodiments '1'h<: method, according to the present invention, is directed to cleaning the fine traction of c:or~taminatcd sandy scol ,end rccoverinf; the hydrocarbons from the said soil by Forming an nqueuus slurry of the fme fraction of the contaminated sandy soil and pruccssing the slurry in a seriies of sequential steps including: scrc;ening the slurry, hcatins the slurry with low pressure stews, separating liyd.cocarl~ns and removing clay and silt from the slurry, thickening the slurry, dev~raterinl; the slurry, washing off the cltl.orides from dewatered sandy soil, as it is shown step by step in Fig.l.
1'he: contaminated sandy soil is composed of a mixture of mineral matter components (sand, clay, silt) containing about 1.U-S.U w/w% oh heavy hydrocarbons, about 0.5-1.5 wlw%
chlorides (e.b.
NaCI, KCl ), small quantities (usually below :500 ppm) of heavy metals (mainly V, Ni, Cr), about fi-27 w/w% water and having pli about 5--9. hand is the; main component (usually over 50 w/w"/o) of the contaminated sandy soil and, as a rule, its particle size varies from 0.001 mm to about 0.5 mm~ with must particles (about ~0-95 w/w%) occurring in the range of 0.04-0.4 mm.
'1"o prepare the soil for processing, according to present invention, an oversize material (> 25.(1 mm~) is rejected by presc~~eening the soil and steel debris arc removed from the soil by, for instance, magnetic separation. The prescreened soil is slurred with hot process wafer contaiuinfi chlorides and the resultant slurry containing 20-5.5 w/w% solids and having temperature in the range of 20°-65°C'. is screened at I.0 mrn. After screening the slurry contains very low percentage (usually <_ l w/w%) of particles in the range of 0.5-1.0 tout. 'The h.ol slurry freed of 1.0 mm pari:icles is directed to a :>lurry heater (h'ig, 2) where it is heated by direct contact with low pre.>sure steatn, under conditions of high agitation and in such a way ihal the heat of steam condensation is quantitatively utilized for raisinfi the temperature of the slurry to ar,y required leva~l of up to 9.9°C. The primary slurry s~~ ubtain ed is directed to a separating/ thickening vessel , of which a schematic; diagram is presented in Fig. 3. ~1"he qeparating/thickening vessel is designE;d, as required by present invcntiort, in such a way that it separates the primary slurry into oily froth stream, a stream of process water far treatment umtaining some oil, chlorides, clay and silt. and a stream of the slurry of precleaned sandy soil (see Fig. 1 ) which is thicken at the bottom of i.he vessel to about 25-b0 w/w % solids_ The separation and densihcation is achieved by maintaining a balance a~rrc~ng controlled agitation (rptn in the range of 10-150) at the bottom of the vessel, very slow downward flow of slurry in the vessel and an upward movement of the stef~rn bubbles heating the Slurry and air bubbles enhancing the collection of oily froth at the top of the vessel. The dense slurry of precleaned sandy soil is further thicken by passing it through., for instance, a cyclone, a screw or, preferably a spiral conccntratar which will raise the solids concentration in the slung of preclcaned sandy soil to about 55-70 w/w% noel fire the precleancd sandy soil from most of clay and silt particles. Thicken (55-70 w/w% solids) slurry of precleaned sandy soil is contacted with hot trealad process water, which reduces solids concentration to about 20-:i5 w/w%, and su abt~tined sltury is directed to another separatingr'thiekening vessel for reprncessing. Reprocessing generates three stt~eams (see hig. 1), namely: a stream of residual oily frotJh, a stream of process water for txcatmcnt and a stream of slurry of clean sandy soil that is thicken at the bottom of thE; vessel to solids concentration in the range of 2~.-60 w/w%. The latter strc;~m is further thicken and deed of residtt~tl clay and silt particles by passing it through a spiral concentrator or a screw t:h.us raising the c;ancentratic~n <of solids in the thicken slutxy of clean Andy soil to abollt .SS-70 w/vv%. The tltick.en slurry of clean sandy soil is dewateted using a conventional type vacuum ifiltcr (e.g. horizontal vacuum belt, vacuum drum) followed by washing the clean sandy soil with iiresh water having temperature of up to 99°C. 'fhe clean sandy soil, generated according to present invention, will meet tlxc 1991 (:CMIJ
(C:anadian C'.ouncil of Ministers for the Environment ) cleanliness criteria for agricultural soil in Canada (2).
When the contaminated sandy soil processed according to the present invention does not have tv meet tha criteria fur agricultural soil because; the sail product is intended for some specific applications like cement Tr~anufacturing, sand blasting, manufacturing silica carbide fibers etc., the processing can be simp:lilied which will result in lowering the capital and operating costs and generating soils with, for instance, very lvw chlorides and high hydrocarbons contents or, high chlorides and very low hydrocarbons contents. To obtain soil product with very low chlorides and high hydrocarbons content~t the processing in the first separating/thickening vessel (see Fig.1 ) will be carried out in such a way that nc,~ prc7c;ess water liar treatment will be withdrawn from this vessel (see Fig. 3) and the slurry of sandy soil generated in this vessel will be directed straight for dewat~~ring and intense washing with hat fresh water. On khe ether hand, when the soil product is to be very low in hydrocarbons and high in chlorides contents the processing will tie carried out as shown in !r'ig.1 using hot healed process water with chlorides content near saturation and the thicken slurry of clean sandy soil will be subjected to dewatcring only.
lnternneaiale concentrations of chlorides and hydrocarbons in the soil product can be obtained by by-pawing eitht;r one or more of the pr~ac;essing steps shown in Fig.l .
S
The. process water for treatment generated as described in the present invention, hav to be treated in order to be recycled to the prcx;ess. 'fhe trc~tmeni is based on separating the free oil and very Line particles of clay and silt (< 0.04 nun) from the process water and this is done by application of cor~amercitcl water treatitug equipment. Jn the present invention, either one or two water treating circuits can he employed. Tlae preferred optic~rt is to use two water treating circuits. When two circuits are employed one, as a rule, is dedicated to treating the process water generated during prccleaning the sandy soil rind the second circuit is dedicated to trcadng all other process water.
Frotn the first water circuit, treating the, txtosi contaminated, high chloride content water, certain amount of wat~:r (about 1 wolutne of u~,ter per 1 voluttte of ally sand processed), is withdrawn continuously and disposedi by injectian into deep disposal well, a salt cavern or by other acceptable means. Equivalc;nt amaunt of water is continuausly supplied to the first circuit from the .second wafer treating circuit. The ~;econd wafer circuit is continuously supplied with fresh water in such quantities that the total volume of process wafer in the; second circuit remains constant.
Opeuation with two eircuit.s allows keepin.6 low ehloridas concentration in the second water circuit and high chlorides concentration (excesdin~ the maximum concentration of chlorides in the oily sand fecxi) in the liral water circuit. Hil;h chloride enncentratiozt in the first water circuit results from chloride buildup due to recycling of proceaa water and from addition of chlorides, if required, to the circuit. It has been found that high chlorides concentration in the first water circuit facilitates separation of ail lTUn1 water phase due to increased density of water phase and l;enerates oily froth of si~niticantly better quality; the froth may cantuin from 40-60 w/w%
hydrocarbon, (on as received basis) and relatively low (below 30 wlw%) concentration of fines.
1'hc oily froth generated during pmcessing c~f oily sand feed, according to present invention, is delivered to heavy oil processing; facility, where it is eomhined with the hulk of heavy oil and proeessEd using c;onventiotts~l methods to rr~cct pipelining specifications.
Having descrihed the foregoing features and advantages c~f the present invention the following examples are provided by way of illustration, but not by Iitnitation.
~XiLTTIpIC 1 A simplified ruaterial balance for a prui:ossing plant dc;signed accordilig 1u present invention (see rig. 1), operating at ambient temperature of about 20°C and pmccssing 1000 tonnes/ day of oily sand is Presented below:
Material In: - ....-..-_, Material ()ut:
Fends Feed Products Product Components Components !. Oily Sand 1.1 Sand (db): 1. Clean Sandy 1.1 Sand 786.0 (ar) 845.5 l Soil (ar) (d6): t 1000 t 1.2 Water: 110.0 864.1 t 1.2 Water:77.7 t t 1...3Oil: 44.5 1.3 Oil: 0.4 t t 2, Steam 1.1 Water: fi0.0 2. Oily Froth 2.1 Uil: 42.1 t (ar) t 60 t 90.7 t 2.2 Clay, 8.4 silt' t 2.3 Water:40.2 L
Background of the Invcnt:ion Ficlld of the Invention: Commercial processes for production of heavy oil/
bitumen generate large quantities of hydrocarbon and salt contaminated soils. in view of tightening environmental regulations and laws, the disposal of such coratarrainated soils is becoming a major iiahility tier the upstream peire~leum industry. There is a need for a technology that could clean the contaminated sandy soils to required cleanliness criteria, recover the hydrocarbons during the cleaning process and accomplish that at a reasonable capital and processing vests.
Description of Yrior Art: Application of commercially available soil washing technologies (1 ) for rcmediation of heavy oil/ bitumen and salt contaminated soils either fails to meet the criteria for residual concentration of contaminants in the product soil or is associated with such high ousts that the upstream heavy oil producc;~~s/ processors are reluctant to seriously consider those teclwologies as a potential solution to their oily sand problem.
The high processing cost of effective soil wsjshint; technologies is usually associated with extensive usage of surfactants, proprietary additives, conditioners and other surface active agents.
To entrance the eiTectiveneas of surface active agents the washing processes are usually carried out at modez~ate (< Stl°C) t~:mpcratures which, in turn, requires extended residence times and may have a negative impact on capital and operating cysts. At elevated (>SO°C) temperatures the torc:cs of physical adsorption, upon which the surf"ace active agents work, are becoming too weak to compete with the vibration forces of heat, C.'.onscqucntly, the surface active agents usually Ioose their effectiveness with an increase in the temperature. However, at sufficiently high temperature the (,physical) adheaian furc~es between; floe c~~ntaminant and the soil particle should be likewise rc;duc;ui.
1t is the object of the present invention to provide a method for effective removal of heavy oil/hitumen and various salts from very !'toe soil particles (< l.Omm) by processing aqueous slurries of these particles at sul~iciently high temperatures, in a system specifically designed fbr this purpose and without the addition of surfac:e active agents.
It is another object of the present invention to provide a system for effective recovery of valuable hydrocarbons trotn the heated sherry of' very fine conttuninatcd soil particles.
These and other objects of the present invention will be apparent from the following description of the preferred embodiments and the appended claims and from practicx of the invenlic~n.
Summary The present invention provides an et~ectiv~ method For cleanup of the fine fraction (_< l.Omm) of corntaminated sandy sUll ~~nd 1'or an efficient recovery of hydrocarbons from the slurry of contaminated sandy soil processed in a system shecific;ally designed for this purpose; the method tnc:ludes the steps of screaming the sandy soil feed to :remove oversize (>25.0 nom) material, preparing hot aqueous stun°y of pre-screened sandy soil, screening the aqueous slurry to remove the ;particles larger than 1.0 mm and heating the resultant slurry to auy required temperature level of up to 99°C in a slurry heater; separating the oily tioth and process water contaminated with oil, clay and silt from the slurred of precleaned sandy soil in a scparatinglthiekening vessel and further lhic;kening the slurry of pre;clcaned sandy soil; contaclinlthe lhiclren slurry of precleaned sandy soil with hot treated pror~ess water and separating in another sepat~dtinl;/thickening vessel the residual oily fiotli and some of the contaminaicd process water from the slurry of clean sandy soil; thickening the slurry of the cleru~ :~rndy sail and dew:~tering the slurry followed by washing the sandy soil with fresh water, having temperature of up to 99°C, to generrate sandy soil containing less than lUUO ~ppm residual hydroc:rrbans, less lhan lUU ppm residual ttrtal chlorides and mewling rather criteria as required by lnterim t~anadian Environmental (duality Criteria for Con tarninated Sites (2).
The; present invention, as sumnaari~ecl above, cleans the sandy soil to a lcvc;l required for depositing thv soil at any suitably located lire without causing any environmental problems or for utilizing the soil product as a fccdstock for some industries. To clean the soil to meet required criteria, the present invent:ican does not require application of any surface active agents which is typical of prior art described under "Description of Prior Art".
Brief Description of the Drawings In the accompanying tigurfa;
Fig.l presents a process diagram ot~ a. system for cleanup of contaminated sandy soils and recovery of hydroc~u-bons, as rcduired by present invention rig. 2 presents, according io present ixivention, a slurry heater for direct stcun heating of sandy soil slurry Fig. 3 presents, according to present invention, a schematic drawing of a separating/thickening vessel for direct steam heating of sandy soil slurry and separating the slurry into oily froth, p.roeess wafer for treatme~rt and thicken slurry of sandy sail De:rcriptio~n of the Preferred Embodiments '1'h<: method, according to the present invention, is directed to cleaning the fine traction of c:or~taminatcd sandy scol ,end rccoverinf; the hydrocarbons from the said soil by Forming an nqueuus slurry of the fme fraction of the contaminated sandy soil and pruccssing the slurry in a seriies of sequential steps including: scrc;ening the slurry, hcatins the slurry with low pressure stews, separating liyd.cocarl~ns and removing clay and silt from the slurry, thickening the slurry, dev~raterinl; the slurry, washing off the cltl.orides from dewatered sandy soil, as it is shown step by step in Fig.l.
1'he: contaminated sandy soil is composed of a mixture of mineral matter components (sand, clay, silt) containing about 1.U-S.U w/w% oh heavy hydrocarbons, about 0.5-1.5 wlw%
chlorides (e.b.
NaCI, KCl ), small quantities (usually below :500 ppm) of heavy metals (mainly V, Ni, Cr), about fi-27 w/w% water and having pli about 5--9. hand is the; main component (usually over 50 w/w"/o) of the contaminated sandy soil and, as a rule, its particle size varies from 0.001 mm to about 0.5 mm~ with must particles (about ~0-95 w/w%) occurring in the range of 0.04-0.4 mm.
'1"o prepare the soil for processing, according to present invention, an oversize material (> 25.(1 mm~) is rejected by presc~~eening the soil and steel debris arc removed from the soil by, for instance, magnetic separation. The prescreened soil is slurred with hot process wafer contaiuinfi chlorides and the resultant slurry containing 20-5.5 w/w% solids and having temperature in the range of 20°-65°C'. is screened at I.0 mrn. After screening the slurry contains very low percentage (usually <_ l w/w%) of particles in the range of 0.5-1.0 tout. 'The h.ol slurry freed of 1.0 mm pari:icles is directed to a :>lurry heater (h'ig, 2) where it is heated by direct contact with low pre.>sure steatn, under conditions of high agitation and in such a way ihal the heat of steam condensation is quantitatively utilized for raisinfi the temperature of the slurry to ar,y required leva~l of up to 9.9°C. The primary slurry s~~ ubtain ed is directed to a separating/ thickening vessel , of which a schematic; diagram is presented in Fig. 3. ~1"he qeparating/thickening vessel is designE;d, as required by present invcntiort, in such a way that it separates the primary slurry into oily froth stream, a stream of process water far treatment umtaining some oil, chlorides, clay and silt. and a stream of the slurry of precleaned sandy soil (see Fig. 1 ) which is thicken at the bottom of i.he vessel to about 25-b0 w/w % solids_ The separation and densihcation is achieved by maintaining a balance a~rrc~ng controlled agitation (rptn in the range of 10-150) at the bottom of the vessel, very slow downward flow of slurry in the vessel and an upward movement of the stef~rn bubbles heating the Slurry and air bubbles enhancing the collection of oily froth at the top of the vessel. The dense slurry of precleaned sandy soil is further thicken by passing it through., for instance, a cyclone, a screw or, preferably a spiral conccntratar which will raise the solids concentration in the slung of preclcaned sandy soil to about 55-70 w/w% noel fire the precleancd sandy soil from most of clay and silt particles. Thicken (55-70 w/w% solids) slurry of precleaned sandy soil is contacted with hot trealad process water, which reduces solids concentration to about 20-:i5 w/w%, and su abt~tined sltury is directed to another separatingr'thiekening vessel for reprncessing. Reprocessing generates three stt~eams (see hig. 1), namely: a stream of residual oily frotJh, a stream of process water for txcatmcnt and a stream of slurry of clean sandy soil that is thicken at the bottom of thE; vessel to solids concentration in the range of 2~.-60 w/w%. The latter strc;~m is further thicken and deed of residtt~tl clay and silt particles by passing it through a spiral concentrator or a screw t:h.us raising the c;ancentratic~n <of solids in the thicken slutxy of clean Andy soil to abollt .SS-70 w/vv%. The tltick.en slurry of clean sandy soil is dewateted using a conventional type vacuum ifiltcr (e.g. horizontal vacuum belt, vacuum drum) followed by washing the clean sandy soil with iiresh water having temperature of up to 99°C. 'fhe clean sandy soil, generated according to present invention, will meet tlxc 1991 (:CMIJ
(C:anadian C'.ouncil of Ministers for the Environment ) cleanliness criteria for agricultural soil in Canada (2).
When the contaminated sandy soil processed according to the present invention does not have tv meet tha criteria fur agricultural soil because; the sail product is intended for some specific applications like cement Tr~anufacturing, sand blasting, manufacturing silica carbide fibers etc., the processing can be simp:lilied which will result in lowering the capital and operating costs and generating soils with, for instance, very lvw chlorides and high hydrocarbons contents or, high chlorides and very low hydrocarbons contents. To obtain soil product with very low chlorides and high hydrocarbons content~t the processing in the first separating/thickening vessel (see Fig.1 ) will be carried out in such a way that nc,~ prc7c;ess water liar treatment will be withdrawn from this vessel (see Fig. 3) and the slurry of sandy soil generated in this vessel will be directed straight for dewat~~ring and intense washing with hat fresh water. On khe ether hand, when the soil product is to be very low in hydrocarbons and high in chlorides contents the processing will tie carried out as shown in !r'ig.1 using hot healed process water with chlorides content near saturation and the thicken slurry of clean sandy soil will be subjected to dewatcring only.
lnternneaiale concentrations of chlorides and hydrocarbons in the soil product can be obtained by by-pawing eitht;r one or more of the pr~ac;essing steps shown in Fig.l .
S
The. process water for treatment generated as described in the present invention, hav to be treated in order to be recycled to the prcx;ess. 'fhe trc~tmeni is based on separating the free oil and very Line particles of clay and silt (< 0.04 nun) from the process water and this is done by application of cor~amercitcl water treatitug equipment. Jn the present invention, either one or two water treating circuits can he employed. Tlae preferred optic~rt is to use two water treating circuits. When two circuits are employed one, as a rule, is dedicated to treating the process water generated during prccleaning the sandy soil rind the second circuit is dedicated to trcadng all other process water.
Frotn the first water circuit, treating the, txtosi contaminated, high chloride content water, certain amount of wat~:r (about 1 wolutne of u~,ter per 1 voluttte of ally sand processed), is withdrawn continuously and disposedi by injectian into deep disposal well, a salt cavern or by other acceptable means. Equivalc;nt amaunt of water is continuausly supplied to the first circuit from the .second wafer treating circuit. The ~;econd wafer circuit is continuously supplied with fresh water in such quantities that the total volume of process wafer in the; second circuit remains constant.
Opeuation with two eircuit.s allows keepin.6 low ehloridas concentration in the second water circuit and high chlorides concentration (excesdin~ the maximum concentration of chlorides in the oily sand fecxi) in the liral water circuit. Hil;h chloride enncentratiozt in the first water circuit results from chloride buildup due to recycling of proceaa water and from addition of chlorides, if required, to the circuit. It has been found that high chlorides concentration in the first water circuit facilitates separation of ail lTUn1 water phase due to increased density of water phase and l;enerates oily froth of si~niticantly better quality; the froth may cantuin from 40-60 w/w%
hydrocarbon, (on as received basis) and relatively low (below 30 wlw%) concentration of fines.
1'hc oily froth generated during pmcessing c~f oily sand feed, according to present invention, is delivered to heavy oil processing; facility, where it is eomhined with the hulk of heavy oil and proeessEd using c;onventiotts~l methods to rr~cct pipelining specifications.
Having descrihed the foregoing features and advantages c~f the present invention the following examples are provided by way of illustration, but not by Iitnitation.
~XiLTTIpIC 1 A simplified ruaterial balance for a prui:ossing plant dc;signed accordilig 1u present invention (see rig. 1), operating at ambient temperature of about 20°C and pmccssing 1000 tonnes/ day of oily sand is Presented below:
Material In: - ....-..-_, Material ()ut:
Fends Feed Products Product Components Components !. Oily Sand 1.1 Sand (db): 1. Clean Sandy 1.1 Sand 786.0 (ar) 845.5 l Soil (ar) (d6): t 1000 t 1.2 Water: 110.0 864.1 t 1.2 Water:77.7 t t 1...3Oil: 44.5 1.3 Oil: 0.4 t t 2, Steam 1.1 Water: fi0.0 2. Oily Froth 2.1 Uil: 42.1 t (ar) t 60 t 90.7 t 2.2 Clay, 8.4 silt' t 2.3 Water:40.2 L
3. Iresh Water3.'t Water: 800.()3. Water for'freatntent3. t Water:852.1 r t g00 ~ and/or Disposal 3.2 Clay, 51.1 silt:: t 905.2 l 3.3 Oil: 2.0 t Total. Feeds: Total feed Total Products: 'Total (_,omp.. ~ Product ,T Comp.:
1860 t 1860 t 18b0 t 1860 t Where : (ar) - as received :for treatment/ analyses (db) - on dry basis "Water for Treatment and/or Dislx~sal"~ in addition to components identified in the table this water contains also I .5 wlw~/o s>r ntc~rc chlorides The sand in the clean sandy soil accounts for about 93°f° of the sand present in the oily sand feed and the oil in the oily froth produc.~t accounts far about 95% of oil present in the oily sand feed.
Tkte oily froth is of reasonably flood quality and contains, on dry basis, about 17% lines. The clean sandy soil contains on dry basis dboul 0.05 w/w% of residual ail, below 80 ppm chlorides and its moisture uanlent is about 10.0 w/w°1°, Example II
ResuGlts of analyses al' a cle~~n sandy soil generated, as described in this invention, from oily sand originating from heavy oil producing facility, are presented belo'NV. The contents of inorganics, hydnncarbons, phcnolics and. others are e~cpressed in ppm.
Gc:nc.~ral Hydrocarbons Phenolics and Qthers & Inorganics pI:f 6-8 HHlagenated.Aliphatics_ Chlorinated Yhenolics < 0_05 ILC: (dsJm)*< 2 Total < U.1 S~,R** <_ 6 Non-Chlorinated Phenolics As < 1U Mono Aromatic ttydrc~carh~ns:(total) < 0.1 Ba ~ 600 Benzene <0.05 Pesticides < 0. t Be , 4 Ediylbenzen<; <:0.I
Ca < 1 Toluene < O.I Mineral Uil and Grease <1000 C'.r (total)< 100 Xylen.e <: U.1 Co < 2U Stv_ rene < U. t Cu < $0 C.rl (total)<: S Polycyclic Aromatic Hydrocarbons Pb ~ 50 (PAH's):
F1g < 0.2 Chlorinated !'AH (totat) ~: 0.1 Mo < 4 Non-chlorinated PAH (total) < 1.0 Ni < 40 1'C:B's < U.5 Se < 2 S < 500 Hctorocyclic Hydroctwbons:
T( v l Furans < (1_ 1 V < 100 Tiophcns < U.I
Zn < 120 Quinoline ~: 0.1 '" RC - hlectrical Condu<;tivity '~* SAIt - Sodium Adsorrtion Ratio Thc. oily sand processing plant, as described in present invention, can generate soil that meats car exceeds the cleanliness criteria required for agricultural soils in most of developed industrialized countries in the world, References 1. H.M_ Freem~ui and I;.F. I~arris, Hazardous Waste R.emediation, Technotnic Publishing Company inc., 851 New Holland Ave, F3c~x 3535, Lancaster, Pennsylvania 17604, USA, 2. Interim C'.antulian HmrirotuttentaI (duality Criteria for Contaminated Sites, C'C:MH JBY(:.-LS34, Wituiipcg, Msnituha, Gan~ula, 19.91
1860 t 1860 t 18b0 t 1860 t Where : (ar) - as received :for treatment/ analyses (db) - on dry basis "Water for Treatment and/or Dislx~sal"~ in addition to components identified in the table this water contains also I .5 wlw~/o s>r ntc~rc chlorides The sand in the clean sandy soil accounts for about 93°f° of the sand present in the oily sand feed and the oil in the oily froth produc.~t accounts far about 95% of oil present in the oily sand feed.
Tkte oily froth is of reasonably flood quality and contains, on dry basis, about 17% lines. The clean sandy soil contains on dry basis dboul 0.05 w/w% of residual ail, below 80 ppm chlorides and its moisture uanlent is about 10.0 w/w°1°, Example II
ResuGlts of analyses al' a cle~~n sandy soil generated, as described in this invention, from oily sand originating from heavy oil producing facility, are presented belo'NV. The contents of inorganics, hydnncarbons, phcnolics and. others are e~cpressed in ppm.
Gc:nc.~ral Hydrocarbons Phenolics and Qthers & Inorganics pI:f 6-8 HHlagenated.Aliphatics_ Chlorinated Yhenolics < 0_05 ILC: (dsJm)*< 2 Total < U.1 S~,R** <_ 6 Non-Chlorinated Phenolics As < 1U Mono Aromatic ttydrc~carh~ns:(total) < 0.1 Ba ~ 600 Benzene <0.05 Pesticides < 0. t Be , 4 Ediylbenzen<; <:0.I
Ca < 1 Toluene < O.I Mineral Uil and Grease <1000 C'.r (total)< 100 Xylen.e <: U.1 Co < 2U Stv_ rene < U. t Cu < $0 C.rl (total)<: S Polycyclic Aromatic Hydrocarbons Pb ~ 50 (PAH's):
F1g < 0.2 Chlorinated !'AH (totat) ~: 0.1 Mo < 4 Non-chlorinated PAH (total) < 1.0 Ni < 40 1'C:B's < U.5 Se < 2 S < 500 Hctorocyclic Hydroctwbons:
T( v l Furans < (1_ 1 V < 100 Tiophcns < U.I
Zn < 120 Quinoline ~: 0.1 '" RC - hlectrical Condu<;tivity '~* SAIt - Sodium Adsorrtion Ratio Thc. oily sand processing plant, as described in present invention, can generate soil that meats car exceeds the cleanliness criteria required for agricultural soils in most of developed industrialized countries in the world, References 1. H.M_ Freem~ui and I;.F. I~arris, Hazardous Waste R.emediation, Technotnic Publishing Company inc., 851 New Holland Ave, F3c~x 3535, Lancaster, Pennsylvania 17604, USA, 2. Interim C'.antulian HmrirotuttentaI (duality Criteria for Contaminated Sites, C'C:MH JBY(:.-LS34, Wituiipcg, Msnituha, Gan~ula, 19.91
Claims (15)
1. A method for cleaning fine (<= 1.0 mm) fraction of contaminated sandy soils and recovering hydrocarbons from aqueous slurries generated from said fine fraction of contaminated sandy sails, the method comprising the steps of:
a/ screening the sandy soil to remove oversize material greater than or equal to 25.0 mm in size and rejecting from the screened sandy soil any steel debris by, for instance, magnetic separation b/ contacting so prepared prescreened sandy soil feed with a hot treated process water containing chlorides to form a hot slurry containing 20-55 w/w% of solids and having temperature in the range of 20-65°C.
c/ screening so obtained hot slurry to remove any oversize material greater than or equal to 1.0 mm in size d/ further heating the hot slurry in a slurry heater to form a primary slurry having temperature of up to 99°C
e/ processing the primary slurry in a separating/thickening vessel and separating said slurry into three streams: a stream of precleaned sandy soil slurry containing w/w% solids, an oily froth stream and a stream of process water for treatment f/ thickening the stream of precleaned sandy soil slurry by passing said stream through a spiral concentrator or a screw, thus forming a stream of thicken (55-70 w/w%
solids) slurry of precleaned sandy soil and a stream of process water for treatment g/ reprocessing the thicken slurry of precleaned sandy soil in a separating/thickening vessel by contacting said slurry with hot treated process water containing chlorides to form a slurry containing 20-55 w/w% solids and separating so formed slurry into three streams: a clean sandy soil slurry stream, a residual oily froth stream and a stream of process water for treatment h/ thickening the clean sandy soil slurry stream by passing it through a spiral concentrator or a screw thus forming a stream of thicken slurry of clean sandy soil containing 55-70 w/w% solids and a stream of process water for treatment i/ dewatering the stream of thicken slurry of clean sandy soil followed by washing said dewatered stream of thicken slurry of clean sandy soil with fresh water using a conventional type vacuum filter (horizontal vacuum belt, vacuum drum) thus generating clean sandy soil
a/ screening the sandy soil to remove oversize material greater than or equal to 25.0 mm in size and rejecting from the screened sandy soil any steel debris by, for instance, magnetic separation b/ contacting so prepared prescreened sandy soil feed with a hot treated process water containing chlorides to form a hot slurry containing 20-55 w/w% of solids and having temperature in the range of 20-65°C.
c/ screening so obtained hot slurry to remove any oversize material greater than or equal to 1.0 mm in size d/ further heating the hot slurry in a slurry heater to form a primary slurry having temperature of up to 99°C
e/ processing the primary slurry in a separating/thickening vessel and separating said slurry into three streams: a stream of precleaned sandy soil slurry containing w/w% solids, an oily froth stream and a stream of process water for treatment f/ thickening the stream of precleaned sandy soil slurry by passing said stream through a spiral concentrator or a screw, thus forming a stream of thicken (55-70 w/w%
solids) slurry of precleaned sandy soil and a stream of process water for treatment g/ reprocessing the thicken slurry of precleaned sandy soil in a separating/thickening vessel by contacting said slurry with hot treated process water containing chlorides to form a slurry containing 20-55 w/w% solids and separating so formed slurry into three streams: a clean sandy soil slurry stream, a residual oily froth stream and a stream of process water for treatment h/ thickening the clean sandy soil slurry stream by passing it through a spiral concentrator or a screw thus forming a stream of thicken slurry of clean sandy soil containing 55-70 w/w% solids and a stream of process water for treatment i/ dewatering the stream of thicken slurry of clean sandy soil followed by washing said dewatered stream of thicken slurry of clean sandy soil with fresh water using a conventional type vacuum filter (horizontal vacuum belt, vacuum drum) thus generating clean sandy soil
2. The method of claim 1, in which screening the hot slurry to remove any oversize material is carried out using a screen with openings not smaller than 1.0 mm and not larger than 5.0 mm
3. The method of claim 1, in which heating the hot slurry in a slurry heater to form a primary slurry having temperature of up to 99°C is accomplished by sparging low pressure steam in a slurry heater and agitating the slurry with an impeller at speeds sufficiently high (20-280 rpm) to prevent sedimentation of solids from the slurry and effective dispersion of low pressure steam
4. The method of claim 1, in which processing primary slurry and reprocessing the thicken slurry of precleaned sandy soil in a separating/thickening vessel is accomplished by balancing the controlled agitation caused by an impeller (rpm in the range of 10-150) with the upward movement of steam and air bubbles and downward flow of a slurry in such a way that the oily froth can be collected and removed from the top of the vessel, the dense slurry of sandy soil particles can be collected and removed from the bottom of the vessel and the process water for treatment can be collected and removed from the central part of the vessel
5. The method of claim 1, in which processing the primary slurry is carried out in two or more separating/thickening vessels arranged in a series and supplied with hot treated process water containing chlorides, in quantities equivalent to process water for treatment withdrawn from said two or more separating/thickening vessels
6. The method of claim 5, in which the product slurry from processing the primary slurry in two or more separating/thickening vessels is directed straight for dewatering and washing with fresh water having temperature of up to 99°C.
7. The method of claim 1, in which reprocessing the thicken slurry of precleaned sandy soil is carried out in two or more separating/thickening vessels arranged in a series and operated the same way as the first separating/thickening vessel
8. The method of claim 1, in which a spiral concentrator is used for thickening the precleaned sandy soil slurry to about 55-70 w/w% solids concentration and separating from said slurry the process water for treatment containing most of clay and silt particles
9. The method of claim 1, in which a spiral concentrator is used for thickening clean sandy soil slurry to about 55-70 w/w% solids concentration and separating from said slurry the process water for treatment containing the residual clay and silt particles
10. The method of claim 1, in which the first separating/thickening vessel for processing the primary slurry is by-passed and the primary slurry is directed straight to a spiral concentrator where most of oily froth is separated together with the process water for treatment and the stream of thicken slurry of precleaned sandy soil is directed for reprocessing
11. The method of claim 1, in which the thicken slurry of recleaned sandy soil does not undergo reprocessing but is directed straight for dewatering and washing with fresh water having temperature of up to 99°C
12. The method of claim 1, in which the primary slurry is processed in the first separating/
thickening vessel in such a way that no process water for treatment is withdrawn from the said vessel and the precleaned sandy soil slurry exiting the vessel is directed straight for dewatering and washing with fresh water having temperature of up to 99°C.
thickening vessel in such a way that no process water for treatment is withdrawn from the said vessel and the precleaned sandy soil slurry exiting the vessel is directed straight for dewatering and washing with fresh water having temperature of up to 99°C.
13. The method of claim 1, in which the streams of process water for treatment generated during processing primary slurry in a separating/thickening vessel and thickening the precleaned sandy soil slurry are treated in one water treating circuit and the remaining streams of process water for treatment are treated in a separate water treating circuit
14. The method of claim 1, in which all streams of process water for treatment are directed to the same water treating circuit
15. The method of claim 1, in which the hot treated process water, containing chlorides and required for preparing hot slurry and reprocessing the thicken slurry of precleaned sandy soil has chlorides content exceeding the maximum concentration resulting from chlorides buildup in the recyle water but lower than saturation concentration of chlorides in recycle water
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2216063 CA2216063C (en) | 1997-11-19 | 1997-11-19 | Method for cleanup of contaminated sandy soils and recovery of hydrocarbons therefrom |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2216063 CA2216063C (en) | 1997-11-19 | 1997-11-19 | Method for cleanup of contaminated sandy soils and recovery of hydrocarbons therefrom |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2216063A1 CA2216063A1 (en) | 1999-05-19 |
| CA2216063C true CA2216063C (en) | 2003-12-09 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2216063 Expired - Fee Related CA2216063C (en) | 1997-11-19 | 1997-11-19 | Method for cleanup of contaminated sandy soils and recovery of hydrocarbons therefrom |
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| CN105057331A (en) * | 2015-08-21 | 2015-11-18 | 无锡乐华自动化科技有限公司 | Soil baking, sterilizing and diluting device |
| CN105057332A (en) * | 2015-08-21 | 2015-11-18 | 无锡乐华自动化科技有限公司 | Soil sterilization and baking device |
| CN105057330A (en) * | 2015-08-21 | 2015-11-18 | 无锡乐华自动化科技有限公司 | Soil sterilizing, baking and purifying device |
| MY200403A (en) | 2017-07-14 | 2023-12-23 | Petroliam Nasional Berhad Petronas | Sand cleaning and disposal system and method |
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1997
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