• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A method for decontaminating waste materials, wherein the residue of water leaching of the roasted chromium mineral containing water soluble hexavalent chromium compounds is wet ground and classified until obtaining such a granulometrical distribution that not more than 5-10% of the particles have an average size larger than 0.4 mm, and 40-60% of the particles have an average size less than 0.8 mm, and is then subjected to wet treatment under vigorous stirring at about 100 DEG C. with sulphur, in an aqueous emulsion of akaline or alkaline-earth sulphide for 1-4 hours, the percentage of solids in the reactor being in the range of 1-60%, preferably 30-35% by weight; and wherein the reacted slurry is thickened and filtered to provide the restored or decontaminated earth and an effluent, which is partly recycled to grinding or to reaction.
    公开号:SU797553A3
    申请号:SU772454656
    申请日:1977-02-23
    公开日:1981-01-15
    发明作者:Гелли Джованни
    申请人:Луиджи Стоппани Ди П. Стоппани Эндк.Соч.Колл (Фирма)；
    IPC主号:
    专利说明:

    (54) METHOD FOR DISINFECTING PRIMED WASTE DURING CHROMINE ORE
    The invention relates to the purification of industrial waste coming from the processing of chrome ore with a sulfur wet process. Solid chromium ore wastes contribute to environmental pollution. When chrome ore is processed, the ratio between production waste number 11i and the finished product, expressed as equivalent sodium bichromate, is often very close to unity. There is a known method for processing household garbage, street litter and other similar materials, including wet grinding and classification followed by treatment of aqueous suspensions in the reactor and filtering the condensed products ri}. However, in the implementation of this method, the processing of chromic ores produces toxic hexavalent chromium compounds, which strongly pollute the environment. The purpose of the invention is to prevent environmental pollution by disinfecting toxic compounds of a valid chromium. This goal is achieved in that the grinding and classification operations are carried out to obtain a product containing 5-10% of particles more than 0.4 mm and 40-60% of particles not less than 0.88 mm, and the treatment of the aqueous suspension is carried out at 100 ° C for 1-4 hours, while elemental sulfur, alkali or alkaline earth sulfide and filtration of the mother liquor are added to the reactor. In this case, the solid waste in the reactor is maintained in the range of 30-35 wt.%. / | 11 bar: alkaline earth sulphide in the reactor at the beginning of the process. The consumption of elemental sulfur is 5% by weight of dry solid waste. The process is based on the reaction between alkali chromate or alkaline earth (contained in the waste to be purified) and sulfur water emulsion in the fir-tree sulfide or alkaline earth emulsion, namely, s-1-11 s 0 - hsp2o h 6 + s alkaline sulphide or alkaline earth at 100 ° C and vigorous stirring; the sulfide, which must be present from the start in the reaction medium, allows sulfur to be dissolved to form a polysulfide, which is particularly reactive. Since the sulfide anion is formed in the reaction between chromium and sulfur (as well as terosulfate), it can be reused by appropriate recycling to the reaction of the final filtered liquid.
    The method is carried out according to a continuous scheme, according to which the waste to be treated is received initially for grinding, where it is subjected to wet grinding with water or recirculating liquid and classified to obtain the required particle size distribution. Thus, the resulting pulp of crushed waste is sent to the reactor, in which sulfur is fed and the final recirculation fluid containing sulphide (sodium sulphide is directly injected into the reactor at the start-up stage), flow from the final phase, or thickener overflow liquid. The diluted slurry of ground (waste) with high dilution leaves the reactor, which passes into the thickener from this apparatus, the overflow liquid returns to the reactor cycle, and the thickened slurry is directed to the filtration system, into which the washing water enters and the filtered mother product leaves, partially recycled to grinding or to the reactor and partially forming the effluent of the installation, for example, for the recovery of thiosulfate and treated waste.
    PRI and MER 1 (laboratory test).
    The number of tests conducted 20.
    The amount of waste to be tested is 500 g.
    The material used before grinding is characterized by the following data: loss at (moisture) 25.0%; grain size (fragile agglomerates) of more than 2 mm 30-35%, less than 2 mm 70-65% water-soluble hexavalent chromium, (75 g per 100 g of waste is brought to a dry state.
    Wet wastes are ground by conventional laboratory technology until the following particle size distribution is obtained:
    More than 0.365 mm 5-10 wt.% More than 0.250 mm 5-10 wt.% More than 0.150 mm 15-20 wt.% More than 0.075 mm 15-20 wt.% Less than 0.075 mm 60-40 wt.% With these granulometric characteristics, which remain unchanged during the reaction in
    the continuation of the whole process, it is possible to obtain good pulp filtrability characteristics
    For each reaction of this example, 500 g of shredded waste, 20 g of sulfur, 180 g of recirculating filtered liquid are loaded into the laboratory reactor per 100 g of the remaining pulp from the previous reactions. After 20 tests conducted at
    Q is the boiling point of the mass (110 ° C) for 1 hour; the following results are achieved (average values).
    The reactive pulp has a specific weight (at 80 ° C) of 1.3 (percentage ratio), solids — 36 g out of 100. Filtered and washed waste is separated from this pulp after filtration; liquid filtered matter, from which, depending on the amount of wash water used, 60 to 70 g should be discharged for every 100 g of treated waste (considered dry), while the remainder is recycled to the reactor. This liquid
    5 has the following characteristics: pH 10.7; equivalent to 0.9 g per 100 g of liquid; (chemical formula Na, .g); equivalent to 4.7 g per 100 g of Ca liquid (expressed as CaO) 1.70 g per 100 g of liquid; Md is absent; Na 0,76 g per 100 g of liquid.
    The recirculated filtered fluid has the same composition.
    5 discharged and is in equilibrium with the reacted waste.
    Example 2 (experienced installation).
    It is the same as in Example 1, but the grinding is done
    0 using a wet method with recirculating filtered product, in a small drum mill, at the end of the reaction the solid solids are separated by means of an experienced rotary vacuum. filter of industrial type.
    For:; each reaction, to the experimental reactor to 150 kg of residual pulp from the previous reaction is loaded
    Q 200 kg of wet-cut waste, which corresponds to 100 kg of dry waste at 110 ° C; 6 kg of sulfur, 100 kg of circulating filtered matter.
    After 10 tests carried out for 1 hour at the boiling point of the mass (), the reacting pulp has a specific weight (at 80 ° C) of 1.25; the percentage of solids is 35 kg per 100 kg.
    60 From this pulp, after filtration, filtered and washed wastes are obtained, having a moisture loss at 22.0% water soluble hexavalent chromium, 0.8 mg per
    45 100 g (1.0 classified as dry waste); the filtered liquid, from which, depending on the amount of industrial water used, 50 to 60 kg of every 100 kg of treated waste should be discharged, the cich is dry, and the rest is partially recycled to grinding and partially to IpeaKTOp. This fluid has the following characteristics: pH 10.9; equivalent to 1.1 kg per 10 kg of fluid; kg equivalent per 100 kg of liquid; Sa, Nd and Na are not defined.
    权利要求:
    Claims (4)
    [1]
    1. A method of disinfecting industrial waste in the processing of chrome ores, which consists in wet grinding and classification, followed by the treatment of aqueous suspensions in the reactor by filtering condensed products, characterized in that, in order to prevent: environmental pollution by disinfecting toxic compounds of hexavalent chromium, Grinding and classification is carried out to obtain a product containing 5-10% of particles more than 0.4 mm and 40-60% of particles less than 0.88 mm, and the treatment of the aqueous suspension is carried out during For 1–4 h, elemental sulfur, alkali or alkaline earth sulfide and filtered mother liquor are added to the reactor.
    0
    [2]
    2. Method POP.1, characterized in that the consumption of solid waste in the reactor is maintained in the range of 30-35 wt.%.
    [3]
    3. Method according to PPL and 2, which is different in that alkaline or alkaline-earth sulphide is fed to the reactor at the beginning of the process.
    [4]
    4. Method POP.1, different from the fact that the consumption of elements.
    20 tons of sulfur is 5% by weight of dry solid waste.
    Sources of information taken into account in the examination
    1. USSR author's certificate
    25 No. 2184, cl. B 03 B 5/00, 1927.
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    同族专利:
    公开号 | 公开日
    BR7701105A|1977-12-06|
    IT1055953B|1982-01-11|
    JPS52131992A|1977-11-05|
    MX146210A|1982-05-26|
    DE2704775A1|1977-08-25|
    ES455970A1|1978-01-16|
    FR2342347B1|1983-06-10|
    US4139460A|1979-02-13|
    PL101477B1|1978-12-30|
    DE2704775C3|1979-08-30|
    JPS558454B2|1980-03-04|
    GB1544882A|1979-04-25|
    DE2704775B2|1978-11-30|
    RO75854A|1982-04-12|
    ZA77835B|1977-12-28|
    FR2342347A1|1977-09-23|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US2350960A|1938-06-07|1944-06-06|Mutual Chemical Company Of Ame|Production and acid treatment of hydrous chromic oxide|
    US2246396A|1938-06-07|1941-06-17|Mutual Chemical Company|Reduction of chromates to produce chromic oxide|
    US2209907A|1938-06-29|1940-07-30|Mutual Chemical Company Of Ame|Manufacture of pigments|
    US3294680A|1964-11-18|1966-12-27|Lancy Lab|Treatment of spent cooling waters|
    JPS5025915B1|1971-02-16|1975-08-27|
    US3810542A|1971-11-26|1974-05-14|Texas Gulf Inc|Process for removing chromium from cooling tower blowdown streams|
    CA1026472A|1972-07-07|1978-02-14|Universite De Sherbrooke|Removal and recovery of chromium from polluted waters|
    US3981965A|1972-08-17|1976-09-21|Allied Chemical Corporation|Suppression of water pollution caused by solid wastes containing chromium compounds|
    US3901805A|1973-10-24|1975-08-26|Dow Badische Co|Removing toxic chromium from industrial effluents|
    US3937785A|1974-09-17|1976-02-10|Allied Chemical Corporation|Treatment of chromium ore residues to suppress pollution|US4207295A|1979-02-13|1980-06-10|Union Carbide Corporation|Processing of chromium ore|
    US4259297A|1979-09-04|1981-03-31|Olin Corporation|Chromate removal from concentrated chlorate solution by chemical precipitation|
    IT1262918B|1992-01-21|1996-07-22|PROCEDURE AND PLANT FOR THE REDUCTION OF HEXAVALENT CHROMIUM CONTAINED IN THE RESIDUES OF THE PROCESSING OF CHROME MINERALS|
    US6607474B2|2000-06-30|2003-08-19|Rmt, Inc.|Method for stabilizing chromium-contaminated materials|
    BE1015759A4|2003-10-31|2005-08-02|Inst Nat Interuniversitaire De|Decontamination procedure for material containing hexavalent chrome, e.g. from glass-making kilns, comprises lixiviation in acid with reducing agent|
    DE602004028034D1|2003-10-31|2010-08-19|Ct De Rech De L Ind Belge De L|PROCESS FOR DECONTAMINATING HEXAVALENT CHROMIUM CONTAINING REFRACTORY MATERIALS|
    JP5407337B2|2009-01-06|2014-02-05|大同特殊鋼株式会社|Treatment method of reduced slag|
    CN111498916A|2020-06-03|2020-08-07|中国恩菲工程技术有限公司|Method for removing hexavalent chromium in process of preparing nickel cobalt hydroxide from laterite-nickel ore|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    IT2051676A|IT1055953B|1976-02-24|1976-02-24|DECONTAMINATION PROCESS OF WASTE MATERIAL COMING FROM THE PROCESSING OF CHROME MINERALS THROUGH WET CONZOLFO TREATMENT|
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