DE2004878B2 - Process for enriching the titanium oxide content in titanium ores - Google Patents

Description

3 4

during the entire digestion period the acid concentration is different for the various

Maintain high acid concentration. suitable for guided prints.

The literature shows that when used, the waste liquor from the first leaching mare contains of steam for heating the amount of Kon as in the known method, all of the densat depends on many factors, some of which, 5 ore-extracted iron in the form of chloride in addition to something like the loss of heat, etc., not readily con-free acid. It turns into hydrochloric acid are trollable. As a result, the reuse recovered varies, with as ancillary propose Process the acid concentration of charge duct iron oxide is obtained, which is supplied to steel mills Batch, which of course means that the quality of the sample can be given. The acid is obtained ducts are also subject to strong fluctuations in the usual way, e.g. B. using the "Aman" method is. On the other hand, only 20% or some other known recovery vapor is used HCl for heating up, so the problem is device.

of the fluctuation of the acid concentration from batch to batch. It is known that a hydrochloric acid of 20% by weight per batch is overcome, and one centimeter of titanium is obtained, the highest concentration that can be obtained with the above oxides of more uniform nature. 15 mentioned or other known recovery for an ilmenite with 55 to 60% TiO ₂ is z. B. procedure can receive. The use of this hot 20% HCl per 1 part of ilmenite, about 2.6 parts by weight of acid, which is obtained indirectly during the recovery process. In practice, the 20% HCl (temperature about 91 ^° C.), together with the consumption for a titanium ore or a titanium-containing one, depends on the iron content and the 20% hydrochloric acid L Vapor form to titanium present acid-soluble components. In order to heat up the digester., Saves the expensive and time-consuming extraction of iron and other acid-dissolving concentration of the 20% HCI, which ensures borrowed substances in the ore, if the azeotropic, constant-boiling mixture is concerned, moderately for a stoichiometric acid over- to a higher concentration, which would be indispensable, from 15 to 20 percent by weight. In the first leaching stage, if steam is used for heating, the prereduced raw material is ex- would. In addition, this measure enables traction with a mixture that consists of the process with a higher degree of efficiency durchzulauge from the second leaching stage a preceding-lead than the known processes in which with the batch plus recovered HCl (Concentrated HCl leached and steamed up 20 percent by weight) in an amount that heats the 30. In addition, the half of the total acid requirement accruing according to the invention (see above) is ent-titanium dioxide of particularly uniform composition. Used for leaching in the second stage.

the remaining amount, d. H. the other half of the The method according to the invention is now through a

total acid requirement, in the form of 20% HCl. As the example explains in more detail,

vaporous 20% HCl used as heating medium 35 _R. . .

becomes, some chlorine e 1 s ρ 1 e during the leaching

hydrofluoric acid condensed; the amount depends on By heating with f'oks for 40 minutes

the construction or the heat loss of the, Dige - around 900 ° C was a »Quilon« obtained in India -

vial, pre-reduced by the leaching time and the urine of the following composition:

initial temperature of the batches and the pre 40 jjq 59 55 y

direction. Fe O 22, Ti %

If you want to achieve a particularly good extraction, then YtO 10 * 77 V

it is expedient to carry out both leaching stages ^ q 1 * 44 V

under a pressure of about 1.4 to 3.5 atmospheres and at gjQ ³ 1 * 41 o °

at a temperature between about 108 and 145 ° C. 45 R ₆₃ * _in particular 'oxides etc! '°

Under these conditions, each level of lavage lasts

about 5 hours. The exact time required depends on yourself - 1 part by weight of the pre-reduced ilmenite was used

understandable from the nature and the characteristics of the leached in two stages, including a total of

Raw material. In the case of ilmenite, 2.6 parts by weight (15% excess) are heated ^{to 100 ° C., as found}

was, in the acid up to 94% of the iron content fresh 20% HCl was used; every stage

solves. The residue contains about 98% of the original - took 5 hours and it was made with 20%

lent TiOj present. HCl steam of 100 ⁰ C directly heated.

In the process according to the invention, after separating and drying, the

Stages a constant boiling azeotropic mixture of ridden ilmenite the following composition:

HCl and water present, the composition of which is 55 jjq 9212 * 7

and boiling point of the prevailing pressure ab- p _e q 2 * 10 V

hangs. For example, the constant boiling pn ^{3 contains} η \ $ y

Acid mixture at 760mm Hg 20.22% HCl (boiling * ^{/ o}

point 108.58 ⁰ Q, at 1000 mm Hg it contains 19.73% The weight ratio of processed ilmenite

HCl and boiling at 116.18 ° C, at 1200 mm Hg contains 60 to raw material was 63 : 100. The iron turned to

it 19.42% HCl and boils at 122.38 ° C. The re- extracted 93.7% , and the yield based on

recovered HCl is on average about 20%, and this TiO _a was 97.5%.

1 sheet of drawings

Claims (1)

ι ² falling iron chloride and the reuse of Claim released hydrochloric acid, and the more recent literature raieniansprucn, ^ b _various suggestions that this Consider the process for the enrichment of the titanium dioxide target (see ζ B FR-PS 1575 768 and containment of iron-containing titanium ores or titanium and GB-PS 1160 667 and ZA-PS 6 802 407, reported in iron oxide-containing slags by leaching in Chemical Abstracts Vol . 70 [1969], p. 184 No. 80 176). Pre-reduced starting material in the digester at A disadvantage of this _R Improve en process up to about 143 ° C under a pressure of up to, however, is then that the Ausauggefaße 3.5 atmospheres with liquid, aqueous-azeotropic 20% is either heated from the outside which (apart from hydrochloric acid, separation of the undissolved solution from heat losses) makes great demands on the remaining titanium dioxide, recovery of the in the material, that means expensive equipment, waste liquor contained hydrogen chloride or that the necessary temperatures and pressures transfer of the dissolved therein Iron chloride can be generated or controlled by introducing steam into the digester and returning the released iron oxide, which then leads to low-level hydrogen chloride in the leaching vessel, which is characterized by the fact that the HCl- Concentration leads. Leach mixture in the digester exclusively by Introduction of 20 percent by weight aqueous chlorine grounds, in the case of the known newer V, .ah, en1 Hydrogen acid in vapor form while heating the leaching mixture in the digester in this way Improve the production of the waste liquors from the treatment in such a way that avoiding the supply of heat recovered hot 20 percent HCl to the vessel from the outside contents exclusively through heats. a means is heated that the acid concentration in the Inside the digester not changed significantly and does not affect the cost-effectiveness of the process 25 pregnant, but on the contrary increased. This problem was solved by the invention The invention relates to the processing of appropriate methods for the enrichment of titanium dioxide ilmenite or other iron-containing titanium ores, such as the content of iron-containing titanium ores or titanium and ilmenite magnetite, ilmenite hematite, or of slag containing titanium iron oxide by leaching out the magnetite or hematite or titanium or iron 3 ° reduced starting material in the digester with up to oxide-containing slags by extracting iron about 143 ⁰ C under a pressure of up to 3.5 atmospheres and other acid-soluble components with chlorine with liquid, aqueous -Azeotropic 20% hydrochloric acid, the title being recovered from the waste eyes obtained from the substance acid, separation of the undissolved titanium extraction, recovery of the dioxide contained in the waste liquor. During processing, ilmenite is obtained in the form of hydrogen chloride components by converting the so-called "synthetic rutile" into an enriched iron chloride dissolved in it into iron oxide and backed ilmenite with a high titanium dioxide content and low levels of the released hydrogen chloride in the iron content, which has particularly good properties. Auslduggefäß, which is characterized by the fact that the leaching mixture in the digester is used in particular as the raw material for the preparation of titanium tetrachloride, titanium dioxide pigments by introducing 20 percent by weight aqueous and other titanium compounds through the "Chk" - hydrochloric acid in vapor form Co-loss "(or" chloride ") method is suitable. Natural rutile is currently the most important raw material for the production of titanium dioxide pigment. However, due to the limited production, the slag is next pre-reduced in the usual way, e.g. B. due to the ability to heat the "synthetic rutile" more and more importantly with coke to around 815 to 1000 ⁰ C or more, as a substitute for natural rutile, if only because the main proportion of ferrous iron in ferrous iron is more versatile than natural, to transfer and at the same time to break the crystal lattice of the ore in important properties, especially in 50, so that the iron is better than the porosity due to the acid, so that it can be attacked in the aforementioned. Reaction with chlorine gas creates a larger contact area. The pre-reduced raw material is then put into a having. vessel lined with acid-proof (dig- Many attempts have therefore already been made to abandon the ester). Into the vessel that was Ilmenite or other iron-containing titanium ore to be processed is kept in slow rotation but only a few led to success. The only hot, 20 percent by weight hydrochloric acid Until recently, technically applied processes were carried out. is the processing of ilmenite by leaching with During extraction (leaching) that is 31.5% hydrochloric acid (HCl of 20 ° Βέ). usual two-stage countercurrent A few years ago, 60 drives were used in this way. However, the warm-up takes place in the commercial quantities of processed ilmenite in this case exclusively through 20% HCl- gained, but the production had to be from economic steam, which is prepared in an HCl evaporator, borrowed reasons and because waste problems arose while with known methods for heating and are given. In particular, the high level of hydrochloric acid needed to maintain the digestion the need and the elimination of the large amounts of at- 65 temperatures and pressures in the digester immediately Falling ferric chloride solution made the procedure water vapor was initiated. According to the invention uneconomical and unsuitable for practice. a dilution of the acid with steam The main aim was therefore to avoid the decomposition of the condensate and in the reaction mixture