DE1178382B - Process for the electrostatic preparation of mineral mixtures - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: B 03 c

German class: Ib-6

Number: 1178 382

File number: K 49507 VI a / 1 b

Filing date: April 18, 1963

Opening day: September 24, 1964

The separation of mineral mixtures into their components in the electrostatic field succeeds in generally not without a pre-treatment of the reprocessed goods. The required different Properties of the individual components of a mineral mixture can be generated in various ways. A purely thermal pretreatment often leads to the goal, but requires in the majority of cases Cases of energy expenditure that endangers the economic viability of the process.

A significant reduction in the required preparation and separation temperatures and thus the energy costs are also due to a chemical conditioning of the material to be processed before to achieve electrostatic separation. Prerequisite for the preparation with the preceding chemical conditioning is that the batch components do not allow rapid charge absorption Have sufficient conductivity at parts of the separation temperature, otherwise the conditioning agent will have an effect is disturbed or canceled. This requirement is usually met at high temperatures, since water or lye films that create conductivity then do not exist. Breakups at room temperature or only slightly elevated temperature, however, succeed very much less often, since - depending on the composition of the material to be processed and the climatic conditions - make conductivity effects noticeable when falling below certain temperatures. This is especially the case in areas with a humid climate.

It is now evident that this interference caused by undesired conductivities can be eliminated are when the mineral mixture is pretreated with air with low water vapor partial pressure and if you have any supply of water to the material to be processed as a result of conditioning with aqueous or solutions containing water.

Pretreatment with air is a known process. However, the previous ones aim Methods of air conditioning maintain or create a selective conductivity of a or more ingredients in the mixture, while the method according to the invention has precisely this conductivity excludes or eliminates.

In German patents 1060331 and 1092401 e.g. B. describes the separation of the carnallite from the accompanying salts. The success of the separation is based on the fact that the carnallite, due to its high hygroscopicity at certain moisture contents of the air with which it comes into contact, processes for electrostatic processing
of mineral mixtures

Applicant: '.

Kali-Chemie Aktiengesellschaft,
Hanover, Hans-Böckler-Allee 20

Named as inventor:

Dr. Gerd Peuschel, Ronnenberg

receives a sufficiently high surface conductivity that its electrostatic separation from the others, allows non-conductive salts. The generation of the necessary for the conductivity separation However, differences in the conductivities of the components due to air conditioning are specific Mineral mixtures are limited, as the mixture components do not differ in most cases withstand sufficient exposure to moisture from the air. So show z. B. in the procedure to separate the carnallite the accompanying minerals of the same, kieserite, NaQ and KCl, which the Components of a hard salt or sylvinite represent a uniform, only different from carnallite Behavior. It was therefore not to be expected that the salts obtained in the separation of carnallitic salts would be lost Allowing knowledge to be transferred to other mineral mixtures.

It was all the more surprising that air conditioning finally succeeded in the divorce to significantly improve carnallite-free potash salts and other mineral mixtures.

The main feature of the new process in contrast to the previously known is that it is not selective at all Conductivities are to be generated or maintained, but that on the contrary during the During the separation process, none of the mineral components have a conductivity that allows for rapid charging on parts the separating apparatus is capable of possessing. This is achieved through treatment with partially or completely dehumidified air. It is crucial that a certain water vapor partial pressure of the same that of the type of mineral mixture, the type of chemical conditioning, if necessary is, and the separation apparatus depends, must be fallen below in order to make the absence more conductive To ensure water or lye films.

409 688/48

the conditioning agents in substance or from anhydrous solvents on the material to be processed be applied.

Before or after the chemical conditioning 5, the mineral mixture is processed according to known methods, z. B. in a rotary kiln, in a fluidized bed, during pneumatic conveyance or already during the grinding of the material to be processed to the grain size required for separation

and the separation can take place at relatively low temperatures - of around 40 ° C and considerably below - be performed.

In addition to air conditioning, a 15 chemical conditioning upstream or connected. It is not always necessary but will be useful in most cases.

The effect of conditioning with moist

In any case, the water vapor partial pressure
the air used for conditioning is below 60%,
preferably below 40%, the vapor pressure one
saturated solution of the mineral to be separated
and for insoluble minerals also below 60%,
preferably below 40% relative humidity
the temperature at which the conditioning and the
Separation to be carried out. The divorce
required charging of the mineral components
then takes place exclusively through contact and air, the water vapor partial pressure of which is necessary for friction without the involvement of conductivity effects, enabling good electrostatic separation

must fall below the required maximum value. At the same time, if necessary, a The goods are heated.

The mineral mixture pretreated in this way is stored in an electrostatic separator of a known type split into its components.

The dependence of the electrostatic separation on the partial pressure of water vapor at different

Low-energy air is generally the same as that of the 20 separation temperatures illustrates the illustration of a thermal treatment. In some cases, before the K ₂ O content of the residues of a Hartallem, the chemical salt separation used, which can be considered characteristic of the Trenn's conditioning agent at low separation temperatures, is successful. The figure shows that the effectiveness of the hard salt used is greater than that of knowing that the hard salt used is more effective with the higher one, the success of the separation after air conditioning with salicylic acid is greater than after heating the mineral treatment with air, which requires Water vapor mixtures. The main advantage of the new process pressure is less than 10 mm Hg when the air conditioning is in the partial or separation temperature should be 28 ° C. With higher complete savings in thermal energy and in separation temperatures, correspondingly higher humidity and the possibility of using the electrostatic separation content of the air, which is used for pretreatment, are also used where a supply of heat is permissible.

energy should be avoided for operational reasons Qualitatively similar curves result if

got to. any other conditioning agent

For example, in processing plants that turn, as well as when other types of potash salts or underground mines are operated, any feed of any other type of ralmixture must be separated. The amount of heat should be avoided, since the cooling of the maximum permissible moisture content of the layers is caused by the weather. Extraordinary difficulties. Conditioning air depends on the combination and costs chemical conditioning carried out on the mine is unsustainable. Such a preparation of the conditioning agent used underground can, however, result in one, in any case it must lead to less than 60%, preferably considerable cost savings that only
the valuable minerals need to be mined
and that for this reason with funding facilities
can be worked, which is a considerably lower 45
Own capacity than those who next to that too
extracting goods to the ballast of the accompanying minerals
have to deal with. The new procedure now allows
the subcontracting of electrostatic systems, there
the separation at such low temperatures due to the partial vapor pressure being below 50. In Table 2 it can be shown how it was previously not possible to carry out the same comparison for others. Mineral mixtures, with Experiment 1 without chemical

Since only exceptionally little, analytically immiscible conditioning was carried out; the The amount of water that can be measured during the air conditioning was only, as described, with humidification Removed from the mineral surfaces, inactivity air is treated.

must, is also the need for dried air. The results given are for purposes only

very low, so that - especially with constant re-examples and restrict the process in generation of the air used - in the least not at all. The effect of pre-treatment with Effort can be worked. Air can be clearly determined from the values in the table

60 will see for the preparation of the mineral mixes.

below 40% of the vapor pressure of a saturated solution of the mineral to be separated or the saturation pressure above water.

Table 1 compares examples of the separation of some potassium salts. Both Tests a) the air contained too high a moisture content: in tests b) the maximum permissible water

as usual, this is comminuted to such an extent that the adhesions are largely broken down and thus in the subsequent divorce in the high-voltage field with a high output concentration

It is of course also possible to use the method according to the invention with others that are already known combine electrostatic methods. So you can z. B. the preconcentration stage with

if the required purity can be obtained 65 carry out air conditioning, Concentration of the pre-concentrate but without the chemical conditioning takes place after such at an elevated temperature. It can also be known Methods. The only thing to note is that it may be beneficial to use at low temperatures

Air conditioning obtained pre-concentrates in a flotation, dissolving process, a magnetic separation or another processing method.

Table to be processed: Potash salts

o / o K ₂ O

Chemical conditioning substance! g / t

pH ₂ O
the
Air ¹ )
mm Hg o / o des
Sati
gearing
value ¹ ) ² ) Tempe
ratur ')
⁰ C the end
prey
% Precon
centrate
% K ₂ O

First post concentrate »/ ο K ₂ O

Hard salt

Hard salt

Hard salt

Hard salt

Hard salt

Hard salt

Hard salt

Sylvinite

Sylvinite

Sylvinite

11.9 * 11.9

11.9 11.9

11.9 11.9

11.9 11.9

11.9 11.9

11.7 11.7

11.7 11.7

15.6 15.6

15.6 15.6

15.6 15.6

lNa lauryl sulfate J powder

Na caprinate powder Al salicylate powder

■ Cd caprinate powder

| Phthalic acid (anhydride powder

! Benzoic acid in methanol solution

[/ i-naphthol powder

Salicylic acid powder

ß-naphthalene (sulfonic acid powder

Fatty acid mixture C ₆ -C ₁₂ in methanol

500
500 11.5
8.5 52.3
39.7 28
28 70.9
92.2 26.0
29.7 500
500 10.6
6.6 48.2
29.8 28
28 81.7
92.3 18.1
27.5 200
200 14.1
5.0 45.5
6.2 35
35 65.8
94.4 16.4
33.0 200
200 14.1
5.0 45.5
6.2 35
35 70.1
95.2 19.2
32.8 500
500 12.8
6.5 41.3
21.0 35
35 75.8
87.7 19.3
26.1 100
100 13.6
8.5 34.0
21.2 40
40 80.1
94.0 25.4
39.6 500
500 11.8
5.6 49.2
23.4 30th
30th 83.6
97.7 21.8
35.5 200
200 14.0
7.0 58.3
29.2 30th
30th 80.3
95.8 24.9
40.2 500
500 12.7
6.2 53.0
25.8 30th
30th 73.4
85.9 22.1
38.8 100
100 14.0
5.5 35.0
13.8 40
40 80.4
95.6 28.9
41.1

35.1 47.4

49.3 58.7

34.5 57.2

40.0 59.7

30.9

55.2

49.2 58.9

*) The values relate to both air conditioning and ² ) Relative to the vapor pressure of a saturated mineral salt solution in the

Tabel

the electrostatic separation,
specified temperature.

No. Reprocessing goods Chemical conditioning
substance ι
g / t PH ₂ O
the
Lufti)
mm Hg Relative
Air-
humidity ¹ ) ² ) Tempe
rature!)
⁰ C the end
prey First
concentrate
o / o content
usable
Mineral *) la
Ib ) Fluorspar with
j 52.2% CaF ₂ { - 14.3
4.2 45.0
13.2 40
40 82.3
92.7 65.0
82.9 2a
2 B \ Fluorspar with
j 52.2% CaF ₂ Phthalic acid in methanol < 100
100 14.4
8.5 45.2
26.6 30th
30th 83.1
95.6 70.2
90.3 3a
3b 1 fluorspar with
J 52.2% CaF ₂ Phthalic Anhydride- J
powder \ 200
200 13.6
9.0 42.7
28.4 30th
30th 82.0
94.7 69.7
85.1 4a
4b \ Fluorspar with
J 52.2% CaF ₂ / i-naphthol powder j 500
500 13.6
9.0 42.7
28.4 30th
30th 85.6
98.5 65.8
89.2 5a
5b \ Barite with
j 88.4% BaSO ₄ Na lauryl sulfate powder < 500
500 13.7
8.7 45.0
27.4 30th
30th 80.0
95.9 93.8
97.2 6a
6b I barite with
J 88.4% BaSO ₄ Fatty acid mixture C ₆ -C ₁₂ J
in methanol \ 100
100 14.2
9.5 44.6
30.0 30th
30th 84.8
94.5 92.9
97.5 7a
7b [Sideritmit
[57.2% FeCO ₃ Fatty acid mixture C ₆ -C ₁₂ j
in methanol \ 100
100 13.9
8.5 43.7
26.6 30th
30th 86.8
95.1 80.7
88.9 OO 00
he ρ Siderite
J 57.2% FeCO ₃ Salicylic acid powder I 500
500 14.9
10.0 46.9
31.4 30th
30th 81.3
94.6 81.4
87.2

*) Trials 1 to 4 = CaF ₂ , Trials 5 and 6 = BaSO ₄ , Trials ¹ J The values relate to both air conditioning and ² ) At the specified temperature.

and 8 = FeCO ₃ .

also to the electrostatic separation.

Claims (1)

Claim: Process for the electrostatic preparation of mineral mixtures, characterized in that that the material to be processed before the separation with partially or completely from the water vapor treated air, namely the water vapor pressure in soluble minerals ralien below 60%, preferably below 40%, of the vapor pressure of a saturated solution of the to separating minerals are and in the case of insoluble minerals also below 60%, preferably below 40%, relative humidity at the temperature at which the conditioning and the separation be performed. 1 sheet of drawings 409 688 / 4S 9.64 © Bundesdruckerei Berlin