Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/02—Froth-flotation processes
• • 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
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/001—Flotation agents
  • B03D1/002—Inorganic compounds
• • 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
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/001—Flotation agents
  • B03D1/004—Organic compounds
  • B03D1/012—Organic compounds containing sulfur
• • 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
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D2201/00—Specified effects produced by the flotation agents
  • B03D2201/007—Modifying reagents for adjusting pH or conductivity
• • 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
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D2201/00—Specified effects produced by the flotation agents
  • B03D2201/02—Collectors
• • 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
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D2203/00—Specified materials treated by the flotation agents; Specified applications
  • B03D2203/02—Ores
  • B03D2203/04—Non-sulfide ores

Definitions

• the invention relates to a process for the preparation of kaolinite by flotation, in particular a process by which kaolin and feldspar can be separated in the finest grain area and both minerals can be obtained in high yield in pure form.
• Kaolinite is a naturally occurring industrial mineral, for whose diverse and different applications as a filler in the paper and ceramic industry, in the plastics industry, in the manufacture of paints, varnishes, rubber and cables, there is a growing and increasing demand.
• Kaolinite arises from exogenous (weather, groundwater) and endogenous (hydrothermal hot solutions, deep vapors) influences with predominantly acidic pH values from feldspar (Ullmanns Encyclopedia of Technical Chemistry, Volume 13, page 509 (1977)).
• feldspar Ullmanns Encyclopedia of Technical Chemistry, Volume 13, page 509 (1977)
• raw kaolin which in addition to the main mineral kaolinite mostly also contains feldspar, quartz and various iron and titanium minerals, is usually carried out by wet processes in which the kaolinite-containing raw earth is suspended in water.
• the following separation process is based on a separation of the different mineral components according to the grain size and the specific weight. Since the minerals quartz and feldspar accompanying the kaolinite are generally coarser ("antiparallel grain distribution"), it is possible to satisfactorily separate the coarser quartz and feldspar from kaolinite down to grain sizes of 20 ⁇ m (cf. M. Clement and HM Tröndle; Erzmetall 22, H. 3, 131 (1969)).
• feldspar is a raw material that is sought after in the ceramic industry
• the separation of kaolinite and feldspar from raw kaolin is aimed at obtaining a feldspar product in addition to the purest possible kaolinite, which meets the high demands for industrial use in glass and Ceramic industry is enough.
• mechanical separation processes in aqueous turbidity are used for this.
• the effectiveness of such separation processes reaches a limit if the grain sizes of kaolinite and feldspar are very close to each other in the fine grain range, since the specific weight of the two minerals (approx. 2.58 g / cm 3 ) is practical is equal to.
• Flotation processes are used in mineral purification practice to remove heavy metal oxides, e.g. Oxides of iron and titanium, removed from kaolinite and thus improve the whiteness of the product.
• Separate processes for the separation of kaolinite from quartz on the one hand and feldspar from quartz on the other hand by flotation of the minerals in the presence of an amine are also collectors from HM Trondle, M. Clement and B. Becher, Interceram 19, 185 and 268 (1970) according to Chemical Abstracts 74, 102589 u (1972). Hydrochlorides and hydroacetates of long-chain aliphatic amines were used as collectors in acidic turbidity.
• polyvalent cations are adsorbed on the surfaces of the mineral particles which are suspended in the aqueous slurry and the flo can affect the minerality of these mineral particles within wide limits (B. Dobias, 6th International Congress for Surfactants, Zurich 1972, page 563 (1973)).
• polyvalent cations are able to react with the collector surfactant to form complex compounds or poorly soluble precipitates, and in this way remove the surfactant from the desired adsorption process on the surface of the mineral particles.
• this reduces the flotation yield unless increased amounts of the collector surfactant are used.
• one and the same multivalent cation can have both activating and deactivating effects in the flotation of mineral particles for the selected collector (surfactant).
• surfactant When which of the two properties dominates can only be determined empirically. As a rule, these effects, whose mechanisms of action are not fully known in detail, are more disruptive than beneficial in the flotation process itself. Preventing the undesired effect of polyvalent cations in the flotation process is therefore a special problem in the preparation of the respective minerals.
• the invention therefore relates to a process for the selective separation of kaolinite and feldspar by flotation in aqueous slurry, which is characterized in that the flotation is carried out at a pH of the slurry, which occurs naturally when the mineral mixture is slurried in water water-soluble salts with trivalent metal ions as activators and depressors and in the presence of cationic or anionic surfactants as collectors and, if appropriate, with the addition of other auxiliaries customary in flotation.
• the pH at which the process is carried out according to the invention is generally in the range between 5 and 8. This pH then results if the solid mineral mixtures are slurried in tap water or fully demineralized water or the mineral mixture is washed out of the rock under high pressure with water jet and brought to light.
• activating acids for example hydrohalic acid or sulfuric acid
• salts of trivalent metal ions are also added to the aqueous slurries as activators or depressors.
• Salts or polysalts of aluminum and iron (III) salts are used.
• the sulfuric salts of trivalent metals are used with advantage.
• the concentration of the salts is in the range from 50 to 2000 g / t, preferably 100 to 1000 g / t, based on the anhydrous metal salt.
• Aluminum salts for example aluminum sulfate, are particularly preferably used according to the present invention. It has been found that the Al (III) ion in aqueous slurries at pH values in the Be - rich to 8 activating effect on kaolinite and deactivating, ie pressing, acts from 5 to feldspar. By adding aluminum salts to the aqueous slurry, concentrates with a higher kaolinite concentration are obtained during flotation. At the same time, the kaolinite output is increased, so that feldspar in a higher purity is also obtained as a flotation residue.
• Cationic or anionic surfactants can be used as collectors in the process according to the invention.
• Compounds from the group of monoalkyltrimethylammonium compounds, dialkyldimethylammonium compounds, alkylarylammonium compounds, alkylamines, hydroxylamines and / or hydroxyalkylamine polyglycol ethers are used as cationic surfactants, the compounds mentioned preferably containing alkyl groups having 12 to 18 carbon atoms.
• Preferred aryl radicals are phenyl and / or benzyl radicals.
• the use of aluminum ions in the separation of kaolinite and feldspar achieved by flotation in particular enables a process to be carried out with the addition of anionic surfactants as collectors.
• the flotation with anionic collectors has surprisingly been found to be particularly advantageous over the flotation with cationic surfactants in that heavy mineral components present in the ore can be separated from the kaolinite before the flotation, which leads to a higher degree of whiteness of the kaolinite concentrate and also an improved quality of the feldspar residue.
• the subsequent processing of the kaolinite is facilitated in that anionic surfactants can be more easily desorbed from the surface of the kaolinite particles than cationic surfactants. It should also be borne in mind that anionic surfactants should be preferred over cationic surfactants due to their environmental behavior alone.
• nonionic additives for example fatty alcohol, alkyl polyglycol ethers and / or alkylphenol polyglycol ethers.
• the concentration of surfactants used as collectors according to the invention is in the range from 50 to 2000 g / t, preferably from 100 to 1000 g / t.
• auxiliaries known to be used in flotation can be added for the separation of kaolinite and feldspar from the aqueous slurry caused by flotation.
• auxiliaries are foaming agents on the one hand or anti-foaming agents on the other hand, which, in contrast to methods known from the prior art, are not absolutely necessary.
• the first component is floated in the mineral mixture of kaolinite and feldspar, while feldspar with surprisingly high purity is obtained as a flotation residue in comparison with processes from the prior art.
• the respective flotation steps are repeated, depending on the quality requirements for the products, a selective separation of the two components being achieved, particularly in the fine grain area.
• a further post-cleaning step is sufficient to obtain concentrates with a kaolinite content between 93 and 97%.
• the kaolinite fraction obtained by flotation is worked up in subsequent process steps.
• the surfactants adsorbed on the surface are desorbed.
• the binding of the surfactant molecule to the negatively charged surface of the kaolinite particles takes place via the ion bridges consisting of trivalent metal ions, so that the anionic surfactants can be desorbed more easily from the surface of the kaolinite than cationic surfactant molecules.
• the quartz content of the raw products in question for the flotative separation of kaolinite and feldspar is due to a previously current separation process extremely low, so that quartz does not have to be separated.
• the flotation experiments were carried out in a Humboldt-Wedag laboratory flotation cell of 1 1 or 2 1 content with a kaolinite / feldspar / quartz fraction with a particle size of 90% less than 20 ⁇ m. This fraction was taken from the intermediate stage of a conventional kaolinite processing plant.
• the selectivity of the flotation i.e. The content of kaolinite and feldspar in the concentrate or in the flotation residue was determined using the known method of loss on ignition (DIN 51 081 for testing ceramic raw materials through change in weight during annealing (July 1979)).
• the minerals mixture was treated 5 min in the flotation cell, wherein, in the examples 2 to 4 activating additives (sulfuric acid and / or aluminum-m i niumsulfat) were added.
• activating additives sulfuric acid and / or aluminum-m i niumsulfat
• the aqueous solution of a cationic collector Araphen R G2D was then added.
• the flotation was carried out with the addition of a commercially available foamer (Araphen R G2 D 1 5 ).
• Example 2 While, according to Example 1 (without activating additives), an extremely poor separation performance of the flotation was achieved both with regard to the kaolinite output in the concentrate and with regard to the kaolinite content in the flotation residue, the selectivity could be improved by the addition of sulfuric acid (Example 2).
• the addition of aluminum sulfate significantly improved the selectivity in the flotation, so that concentrates with a high kaolinite content were obtained in a single post-cleaning step.
• cetylpyridinium chloride as a cationic collector, a significant increase in the selectivity of the separation and an increase in the amount applied were measured when aluminum sulfate was added.

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• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Silicates, Zeolites, And Molecular Sieves (AREA)
• Paper (AREA)
• Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)
• Treatment Of Sludge (AREA)

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• 1985
  • 1985-02-27 DE DE19853506808 patent/DE3506808A1/de not_active Withdrawn
• 1986
  • 1986-02-20 DE DE8686102193T patent/DE3682916D1/de not_active Expired - Fee Related
  • 1986-02-20 EP EP86102193A patent/EP0193109B1/fr not_active Expired - Lifetime
  • 1986-02-20 AT AT86102193T patent/ATE70469T1/de not_active IP Right Cessation
  • 1986-02-26 US US06/834,072 patent/US4714544A/en not_active Expired - Fee Related
• 1987
  • 1987-09-14 US US07/096,706 patent/US4744892A/en not_active Expired - Fee Related

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