DD140708A5 - METHOD FOR THE FINISHING OF COAL - Google Patents

Description

The present invention relates to the upgrading of raw coal by removing certain impurities therefrom.

Characteristic "of the known technical solutions

The removal of pyrite and other impurities from raw coal by a magnetic process is known, but the success of the process depends on an efficient process for selectively increasing the magnetic susceptibility of the pyrite particles prior to magnetic separation. While carbon particles alone are slightly diamagnetic, pyrite and many other mineral contaminants have weak paramagnetic properties, yet their paramagnetism is not yet sufficient to economically affect coal deposition. However, effective reduction of coal is possible if the magnetic susceptibility of the pyrite or other impurities is increased. "Estimates have shown that converting less than O _{5 to} 1 % of the pyrite in pyritic carbon to ferromagnetic iron compounds provides a sufficient increase in the carbon content magnetic receptivity is achieved «

US Pat. No. 3,938,966 discloses a coal upgrading process in which the raw coal is treated with substantially undecomposed

Berlin, the 10th · 7th 1978 GZ 52 702 18

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Iron carbonyl which changes the perceptible magnetic susceptibility of certain impurity components in the raw coal, thereby enabling their removal by means of low-power magnetic separators. "This process represents a noteworthy advance in the art since the treatment of some carbonates by the said process is such impurities pyrite, which is mainly responsible for sulfur dioxide Verßchmutzungsprobleme ₉ can substantially remove "However, although some types of coal by this treatment get a v / magnetic esentlieh higher capacity _s talk others not so much a matter of"

Object of the invention. · ·

The aim of the present invention is to improve the process according to the prior art.

This is achieved according to the invention by a pretreatment of the coal, in which the coal is heated to at least one such temperature over at least such a period that a time-temperature ratio of

is reached or exceeded, where D is the time in hours and T is the temperature in degrees Celsius, and wherein the temperature is not less than 95 ⁰ G and K at least caβ 0-5 *

Berlin, July 10, 1978 GZ 52 702 18

• - 3 - 2 03 33 8

The process of the present invention can be applied to coals of general origin as long as the coal contains one or more impurities that respond to the metal treatment. In the basic process, a metal treatment is used to increase the magnetic susceptibility of an impurity. By selective enhancement of this property of the contaminant, but without affecting the coal itself, magnetic separation can be carried out in conventional form to remove the contaminant from the coal. The coal then remains in a purer state, making it more suitable for incineration *

The phrase "increasing the magnetic susceptibility" of a particle or an impurity as used herein is defined by the following explanation: Each compound of any type has a specifically defined magnetic susceptibility, which is understood to mean the total attraction of the compound by a magnetic force A change in surface properties changes the magnetic susceptibility, and metal treatment in the basic process modifies the surface properties of an impurity to increase the magnetic susceptibility of the impurity

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that the magnetic susceptibility of the particle is not actually changed, but the particle itself, at least its surface is changed, resulting in a particle having a stronger magnetic susceptibility than the original impurity "Increasing the magnetic susceptibility" of the particle or the impurity itself ".

Impurities for which the process of the present invention can be used are those impurities that can react with one or more of the metal compounds described below to form a product having increased magnetic susceptibility. Examples of such impurities are pyrite, ash-forming minerals such as clay and Slate species and various sulphates, such as calcium sulphate and ferrous sulphate, are included. For purposes of explanation, the following description refers to pyrite, but this is not to be understood as meaning that other suitable contaminants could not be similarly treated

Numerous metal-containing compounds are suitable for imparting this magnetic susceptibility. It is believed that several different mechanisms are involved in the so-called "treatment" and / or "reaction" to increase the magnetic susceptibility, depending on the metal-containing compound or compounds Some metal-containing compounds, in which the metals are more magnetic than the impurities, especially iron, under certain circumstances contaminate the metal, thereby increasing the magnetic susceptibility of the impurity. "Some metal-containing compounds attack the pyrite by reacting with a part of the pyrite

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This mechanism can be explained by the following reaction scheme:

6M + 7FeS ₀ - * ► Fe_, S _Q + 6 MS

Similarly, constituents of the ash, such as Pe ₂ O ₃ , can react with a metal to form a more magnetic compound, such as by the following reaction:

M + 3Fe ₂ O ₃ -e-MO + 2Fe ₃ O ₄

Similarly, US Pat. No. 3,938,966, and the reaction mechanisms described therein with respect to pyrite and iron pentacarbonyl, provide opportunities for increasing the magnetic susceptibility of contaminants.

Undoubtedly, other mechanisms also contribute to increasing the magnetic susceptibility, and in this case as well, the metal-containing compounds or compound used and the reaction conditions are again the determining factors. It is self-evident that, due to the many variables involved, within the scope of the disclosures set forth herein However, for each and all compounds, the choice of a particular metal compound can not be specified together with the most appropriate reaction conditions that must be used for the particular compound. "However, the proper choice will not be a problem for a skilled person with minimal experimentation and here It is sufficient to note that the improvement described herein relates to all of these compounds

Many organic iron-containing compounds have the ability to increase the magnetic susceptibility of coal contaminants as long as the compound is involved

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suitable / that the iron in the compound can be brought into contact with the impurity under conditions which can cause a change of at least a part of the surface of the impurity. Suitable organic iron-containing compounds capable of exerting sufficient vapor pressure, the iron being present as a component in the vapor, bringing the iron into contact with the contaminant at the reaction temperature, other organic iron-containing compounds are also suitable. which can be dissolved and / or "dusted" and brought into contact with the contamination «

Preferred compounds in the vapor pressure group are those which have a vapor pressure, with iron present as a component in the vapor, of at least about 10 millimeters of mercury, more preferably at least about 25 millimeters of mercury, and most preferably at least about 50 millimeters of mercury at the reaction temperature can exert _e examples of groups that are within the scope of this definition vapor pressure, ferrocene and its Drivate and beta-diketone iron "Specific examples include ferrocene, pimethylferrocendioat, 1,1'-ferrocene dicarboxylic acid, iron (IIl) acetylacetonate and iron (II ) acetylacetonate "

Other organic compounds that may be used to increase magnetic susceptibility include those that can be dissolved and contacted with the impurities. These compounds must have sufficient solubility to provide enough metal for contact with the surface of the contaminant is available «. The solubility should preferably be at least about 1 gram per liter, but preferably at least about 10 grams per liter and most preferably at least about 50 grams per liter at the initiation temperature. Of course, the solvent must have the abovementioned abilities and should not cause any problems as a result

Side reactions which would reduce the efficiency of the process cause "Suitable solvents include, for example, acetone, petroleum ether, naphtha, hexane and benzene. * Of course, their choice depends on the particular metal compound to be used. ,

One grouping that complies with this definition of the solution includes the carboxylic acid salts of iron, and specific examples include iron octoate, iron naphthenate, and iron stearate ©

Various inorganic compounds are also capable of increasing magnetic susceptibility. Preferred inorganic compounds include metal carbonyls, such as iron, nickel, cobalt, molybdenum, tungsten, and chromium carbonyls, and derivatives of these compounds Susceptibility is especially preferred for iron carbonyl, especially iron pentacarbonyl, iron dodecacarbonyl and iron nonacarbonyl

The metal-containing compound most suitable for increasing the magnetic susceptibility is iron pentacarbonyl. The process is carried out so that the raw coal to be separated from pyrite or other impurities is contacted with iron carbonyl under conditions where insufficient dissociation of carbonyl takes place in the metal and carbon monoxide, so that is brought about no substantial deposition of metal on the particles of coal "These conditions are the temperature, the nature of the carbonyl ,, the pressure Gaszusamniensetzung etc _e dictated" Usually, the Carbonylgas to a temperature heated, which is under the reaction conditions immediately below its decomposition temperature "For the bringing together of iron carbonyl and

Coal can be used in a variety of available equipment, such as a rotary kiln, which serves as a reaction vessel in which the vapors of iron carbonyls are brought into contact with the swirling furnace contents by a gas such as nitrogen »

When carbonyl is used as the magnetic susceptibility enhancer, the process must be carried out at a temperature lower than the temperature at which most of the carbonyl decomposition proceeds under the reaction conditions, so that there is a possibility that the iron When the temperature is raised above the decomposition temperature, the selectivity of the process for increasing the magnetic susceptibility of one or more impurities is adversely affected without affecting the coal

It is most advantageous when the treatment with iron pentacarbonyl is carried out so that the carbon with the carbonyl over a period of about 1/2 to about 4 hours at a lying between about 150 ⁰ C and about 200 ⁰ C temperature and a carbonyl concentration of about 2 to about 16 kilograms per ton of coal is brought together *

For efficient separation of the pyrite from the coal, the coal should be minced to such a fineness that pyrite particles are free or nearly free of carbon particles. "The degree of fineness required depends on the size distribution of the pyrite in the coal." A detailed discussion of the subject of coal for power plants can be found in the article titled "Pyrite Size Distribution and Cobalt Pyrite Particulate in Charcoal," US Bureau of Mines, Investigation Report 7231 "The Demand of Separation

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of pyrite applies to all physical divorce and is not a particular disadvantage of the present invention. In addition, modern coal-fired power plant technology requires 60 to 90 percent of the coal to be reduced to a -200 fineness prior to incineration.

The improvement on which the process according to the invention is based relates to the pretreatment of the raw coal before the reaction with the metal-containing compound is initiated »

The process of the present invention is particularly suitable for the removal of elemental sulfur from the coal. In general, the level of elemental sulfur in the raw coal is at least about 10 parts per million, and often over several hundred parts per million.

Concentrations of elemental sulfur in excess of 10 parts per million hinder the reaction to increase "magnetic susceptibility. Larger levels of elemental sulfur are a major obstacle." It is therefore understandable that any removal of elemental sulfur from the implementation of the Preferably, the concentration of elemental sulfur after treatment to remove it is less than about 200 parts per million (ppm), more preferably less than about 50 ppm, and most preferably less than about 10 ppm by weight to the total mass of the raw coal to be treated ·

As a pretreatment, in principle, any process for removing elemental sulfur from raw coal can be used, and examples of such processes are heat treatment, steam treatment, solvent extraction and chemical reaction.

This pretreatment consists essentially of the heating

Coal, so that the coal and the impurity respond better to the reaction to increase the magnetic susceptibility ,, The temperature and the heating time are interdependent, and in general, higher temperatures require a shorter time »It is generally advisable to reduce the temperature and the Duration to be chosen in accordance with the following equation:

, f 50 ³ DK

T - 90

where D is the time in hours and T is the temperature in degrees Celsius and where K is preferably at least about 0.5, more preferably at least about 5, and most preferably at least about 25. The equation is not exact for temperatures below about 95 ° C. Some improvement can be achieved at temperatures below 95 ⁰ C, but the required duration would then be excessively long. In cases where the temperature exceeds the combustion temperature of the coal, the time to prevent combustion must be very short and should, if possible, be the value the equation does not significantly exceed "Additionally have other known cautions are observed in the field ·

When operating within the conditions of the time-temperature equation discussed above, it is generally preferred that the pretreatment in heating the coal be maintained at a temperature of at least about 100 ^° C., more preferably at least about 150 ^° C., and on best to a temperature of at least about 170 ⁰ C is »This heat treatment should last at least about 1 hour, more preferably at least about 2 hours»

The heat treatment does not have to follow immediately the reaction to increase the magnetic susceptibility. "So the coal can not reach room temperature or any other room temperature

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cool down to another appropriate temperature before the reaction to increase the magnetic susceptibility is made ·

In general, it is favorable if the temperature for the heat treatment is at least slightly above the temperature of the reaction to increase the magnetic susceptibility. This is not a strictly necessary measure, but the results are generally better. It is believed that by the heat treatment Thus, if the reaction to increase the magnetic susceptibility is carried out at a temperature above the pretreatment temperature, then it is possible that further volatiles may cause the reaction to increase the magnetic susceptibility could adversely affect magnetic susceptibility slightly *

The heat treatment step may be carried out in the presence of one or more gaseous additives, and this is advantageous under many conditions; examples of suitable gaseous additives are nitrogen, steam, carbon monoxide, carbon dioxide, ammonia, methane, air, ethane, propane, butane, and the like other hydrocarbon compounds present in the gaseous state at the pretreatment temperature »

, When these additives are used, it is best to use them in an amount of at least about 1.2 and more preferably at least about 12 and most preferably at least about 120 cubic meters per hour per tonne of processed coal. "

A particularly preferred additive is steam. The heat pretreatment with steam is preferably carried out in a temperature

range between about 100 ^° C. and about 300 ^° C., more preferably between about 150 ^° C. and about 225 ^° C. The pretreatment should be carried out for at least about 15 minutes, preferably at least about 30 minutes, and preferably at least one hour. The amount of water should be from about 2 % to about 50 %, more preferably from about 5 % to about 30 %, and most preferably from about 10 % to about 25%, by weight of the treated "coal"

A particularly favorable technique for carrying out the pretreatment process according to the invention consists in the course of the process / wherein the coal is in the fluidized state. Conventional fluidized bed apparatuses and processes are suitable for this process. This fluidized bed treatment facilitates the thorough pretreatment of the entire coal. dererse.its the coal can be treated with a solvent or a combination of solvents to remove elemental sulfur «.

Examples of suitable solvents are carbon tetrachloride / toluene, acetone, ethyl alcohol, methyl alcohol, ether, liquid ammonia and other compounds which are suitable for dissolving elemental sulfur. Preferred solvents are carbon tetrachloride, petroleum ether and hot toluene and subsequent rinsing with warm acetone.

The amount of solvent used will depend on the degree of solubility of the elemental sulfur in the treatment toner · in the solvent. In general, it is desirable to use the solvent in an amount of at least about 500, more preferably at least about 1000, and most preferably to use at least about 2000 milliliters per kilogram of coal «

The step for the removal of the elemental sulfur does not necessarily have the immediate reaction to increase the

2 ft ft ft Π Ί *? 4

follow magnetic susceptibility. Thus, the coal can be readily stored for an arbitrarily long time before the reaction to increase the magnetic susceptibility.

Au sführ ungsbeispiele:

In all the examples given, the chemically treated coal samples were separated in a magnetic separator to obtain a non-magnetic pure carbon content and a magnetic fraction of waste.

Example 1:

A sample of Illinois No. 6 charcoal was dry sieved and 75 grams of 14 mit 150 mesh was roasted at a temperature of 190-195 ° C for 12 minutes and iron pentacarbonyl at 7.5 kilograms per liter ¹ tonne of charcoal treated / the carbonyl was co-produced in a nitrogen atmosphere. A charge of similar charcoal was pretreated by heating to 200 C with 15 minutes passage of humid air through the reaction vessel followed by passage of dry air for five minutes and then into treated the same way with iron carbonyl. Both samples were subjected to magnetic separation and had the analysis given in Table 1.

Table 1: Coal without preparation Vorbehandel th coal feedstock pure coal feedstock re a coal 30/4 3/89 15/5 3/90 31/4 4/03 12.2 2/37 - · 64/0 - 59.3 Ash (%) Pyrite Sulfur (%) Yield QQ

Example 2:

A sample of Illinois coal as in Example 1 was treated for 30 minutes at 190 to 195 ^° C. with 7.5 kilograms of iron pentacarbonyl per tonne of carbon carried in a nitrogen atmosphere. An identical sample was treated in the same manner but became the coal for 30 minutes pretreated at 190 to 195 ⁰ C with a nitrogen gas in a "rate of 200 cubic meters per hour per ton of coal and VVasserdampf in an amount of 21 kilograms per hour per ton of coal" As table 2 shows, was in the coal detect a greater reduction in ash and pyrite sulfur after magnetic separation ₀

Table 2: * Coal without Vorbehandlunq Pre-treated coal pure coal Ash (%) pyrite sulfur (X) feedstock pure coal feedstock 11.2 2.87 Yield (%) 20.2 3.69 12, 4, 29.4 3/63 56.9 Example 3: - 56 - , 2, 48 , 5

Treatment of 75 grams of Lower Freeport coal with 16 kilograms of iron pentacarbonyl per ton at 170 ^° C. over a period of one hour under a nitrogen flow of 250 milliliters per minute during heating and cooling resulted in a product yield of 56.9 % Ash content of 22.5 % and pyrite sulfur content of 1.85 % _f Pretreatment of the Lower Freeport coal with heat and / or steam under different reaction conditions followed by the same carbonyl treatment as described above resulted in greater reductions in ash and pyrite sulfur in the pure coal · The raw coal had a screen fineness of 14 χ 0 _β for all samples. The pretreatment conditions

and the analysis of the pure coal are listed in the following table.

table 3: conditions for safe use Time min Dampfkonze % Atmos · Erqebnisse ash Pyrite, % Temp. ° C 22.5  • 1/85 10 0 11.2 1.13 190 10 25 13.1 1.45 Sample No. 190 10 89 pure coal product 10.6 0.84 No pretreatment Variable conditions 190 10 0 Yield wt,% 13.5 1.23 1 260 10 28 56.9 13.9 1.02 2 Water ml / min 260 10 98 54.5 18.7 0.84 3 260 30 0 52.6 15.7 0.59 4th - 190 30 25 55.8 12.0 0.53 5 0.95 190 30 89 71.4 11.5 0.37 6 3.35 190 30 0 69.7 18.6 1.27 7 0 260 30 28 81.2 14.8 0.77 8th 0.95 260 30 98 73.9 16.4 0.58 9 3.35 260 - - 68.3 28.1 1.76 · 10 0 - 68.1 11 0.95 65.6 12 3.35 75.3 0 78.6 0.95 - 3.35 Raw coal Example 4:

Table 4 shows the effect of feeding different gases during the preconditioning treatment with steam on the results of the iron carbonyl process on Lower Freeport coal. * The same conditions in all tests included a 75 gram batch of Lower Freeport coal with a screen fineness of 14 χ 0 which was heated to 200 ^° C for 60 minutes (including heating and cooling in 250 milliliters of N ₂ per minute) using water vapor

was initiated during the experiment in an amount of 0/46 grams per minute. As can be seen from Table 4, different gases were supplied during the steam pre-treatment · Treatment rait carbonyl was in all tests for an hour ι at a temperature of 170 ⁰ C pentacarbonyl per ton carried out "

long at a temperature of 170 ⁰ C with 16 kilograms of iron

Example 5;

Both with steam (obtained from 192 kilograms of water per tonne of coal and fed over a period of one hour in a coal chamber at 200 C) and with heat (for 30 minutes at 130 ⁰ C by a N ^ -stream of 1.7 Liters per minute) pretreated Lower Freeport coal with a sieve fineness of 14 χ 0 was treated with various organic iron-containing compounds / as indicated in Table 5. The coal was gradually heated to the indicated temperatures and the iron compound evaporated outside The iron (III) acetylacetonate was dissolved in acetone and mixed with the charcoal, followed by drying in a stream of nitrogen. The coal was then gradually heated to operating temperature, with the temperature slowly rising to the was increased. "

Figure 6:. '

Three identical samples of Pittsburgh coal, mesh size 14 x 0, which contained 17.9% ash and 1.67% sulfur pyrite were treated with 8 kg Eiesenpentacarbonyl per ton for 60 minutes at a temperature of 190 to 195 ⁰ C " sample No. · 1 has not been pre-treated "sample No. ₀ 2 was mixed with 95 kg of steam per tonne for 60 minutes pre-treated at a temperature of 190-195 ⁰ C," the coal of the sample no. was charged with 95 kg of steam per tonne of 60 minutes . Long pretreated at a temperature of 250 to 255 ⁰ C. All samples

Table 4

Sample. No 1 pretreatment

Conditions:

Gas - N ₂ CO CO ₂ N ₂ "N _£ tuft N ₂ NH _3" N _{£ £} S0 N N _{£ £ £} butane N

Flow, ml / min - 150 50 100 27 123 150 150 50 100 50 100 150 5p 10 <

Duration, Minutes - 1-60 1-60 1-60 1-60 1-60 1-30 31-60 1-60 1-60 1-60 1-60 1-60 1-60 l-i

Yield _{7 -} Gq \\ "%

pure coal 56 ₇ 9 69.6 77.4 72.3 73.9 89.8 61.3 61.2 61.8

Ash, %

pure coal 22.5 13.3 17.7 15.9 15.3 25.1 11.9 15.3 9.6

Pyrite sulfur, %

pure coal 1.85 0.40 0.52 0.47 0.42 1.0 0.57 0.44 0.31

The coal used contained 29.9 % ash and 1.63 % pyrite sulfur

Table 5: conditions kg / t Time at max temp 1 2 sample Analysis of pure coal Pyrite sulfur, % Max »Temp. ⁰ C 16 16.2 1 1 3 4 steamed dried Yield wt% Ash / ο 1.41 1.75 275 275 7.9 9.7 1 1 5 6 steamed dried 74.1 69.5 23.8 24.1 1.47 "1.56 connection 275 275 13 16.4 1 1 7 p steamed dried 81.0 74.0 25.3 23.6 1.41 1.32 ferrocene 275 275 15 15.6 1 1 9 10 steamed dried 77.2 70.5 22.7 24.3 1.46 1.49 Ferrocene carboxylic acid 275 275 16 16.1 0.33 0.33 - steamed dried 79.1 67.8 24.0 24.2 1.31 1.64 acetylferrocene 285 285 - - 75.1 75.3 22.4 22.7 1.76 ' Dimethylferrocene difoate - -'Λ 100 28.1 Iron (III) acetyl acetonate Feedstock (untreated)

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were treated with iron pentacarbonyl in the same manner. The steam pretreated coal had a greater reduction in ash and pyrite sulfur contents, as shown in Table 6.

Table 6: preparation , Yield, wt.% Ash, % Pyrite-sulfur ^ no steam (190-195 ° C) steam (250-255 ° C) 84.6 84.0 86.5 10.8 9.0 10.0 1.09 0.83 0.93 sample el 7th: 1 2 3 Beispi

A bituminous Lower Freeport coal from Pennsylvania was applied to a S, iebfeinheit of 14 crushed χ 0, and the samples were incubated for 60 minutes with 16 kg of iron pentacarbonyl per ton of coal at a temperature of 170 ⁰ C treated sample No. 1 was not pretreated, In experiments 2 to 13, carbon samples of 125 grams each were used, which were dried at different temperatures for various periods of time in metal pans of 19 χ 19 χ 4.5 cm in a large circulating air dryer. The dried samples were stored in a nitrogen atmosphere until treatment with carbonyl. The temperature and duration of these pretreatments are shown in Table 7,

Example 8i.

A sample of Illinois coal No. 6 was moistened with water and then dried in a fluidized bed reactor with synthesis waste gas of 5.5% O _2, 12.9% CO ₂ and 81.5% N ₂ for 15 minutes at a temperature of 305 ⁰ The sample was dried (after only two years, stored under nitrogen to prevent decomposition) for 60 minutes with 16 kilograms of iron pentacarbonyl per ton

treated at a temperature of 170 ⁰ C · After magnetic separation, the pure formed Kohle'78,8% of the starting material with an ash content of 17.1% and a content of pyritic sulfur from 1.33% * The feed coal had an ash content of 30.4 % and a pyrite-Schvvefel content of 3.89 %, and this coal hardly responds to the iron carbonyl treatment in terms of pyrite removal without pretreatment.

Example 9:

Pittsburgh coal containing 25 ppm elemental sulfur, 17.9% by volume ash and 1.67% by weight pyrite-Schvvefel was crushed to a sieve fineness of 14χ0 and containing 8 kilograms of iron pentacarbonyl per tonne at a temperature of treated for about 190-195 C for 60 minutes. Magnetic separation was carried out after treatment with carbonyl. In Experiment 1, no pretreatment was carried out to remove elemental sulfur, and in Runs 2-5 a pretreatment with HiI - fe was carried out Process for removing as much as possible of the total elemental sulfur prior to reaction with carbonyl. Table 1 (? 9) indicates the yield of pure coal from each weight percent based trial of the raw coal used and the weight percent ash and pyrite sulfur of the pure coal *

Table 7:

No <sample ~

Variable pretreatment conditions

Temp, ⁰ C

Time, h

123 2 178 2 225 2 123 8th 178 8th 225. 8th 123 16 178 16 180 16 225 16 123 48 178 48 225 48

Results of the pure coal product

Yield, wt% _e

Ash,

Pyrite-S,

56.9 22.5 1.85 69.6 23.6 1.67 77.8 16, S 0.63 89.2 23.9 0.57 66.3 24.2 1.74 84.3 18.6 0.60 86.7 22.0 0.72 60.1 19.3 1.39 87.9 20.8 0.56 85.5 16.6 0.59 88.6 23.5 0.68 59.1 16.5 1.04 88.5 22.3 0.63 87.5 23.0 0.72

Table 9:

Method for S Analysis of 84.6 pure coal Attempt- Sulfur removal <PPm) _Au8 - _{booty #} 84.0 Ash, Pyrite sulfur, O / n No" none 25 85.9 10.8 1.09 1 S with toluene and <1 acetone removed 84.0 9.3 0.90 2 S removed with petroleum ether <1 86.5 9.4 0.85 3 S with steam, 95 kg / t, <1 190 - 195 ⁰ C, away 9.0 0.83 4 S with steam, 95 kg / t, <l 250 - 255 ° C, removed 10.0 0.93 5 10: example

A bituminous Lovver-Freeport coal from Pennsylvania, which contained 156 ppm of elemental sulfur, was added to a mesh size of -14 crushed Two samples were treated with 2 kg of iron pentacarbonyl per ton at a temperature of about 190-195 ⁰ C * Sample 1 was not pretreated to remove elemental sulfur, on the other hand sample # 2 was treated with hot toluene and rinsed with warm acetone prior to carbonyl treatment. "Comparable results are shown in Table 10".

Table 10:

Charcoal pure coal

Trial. Ash pyrite-S S yield ash pyrite-S

No, (% by weight) (% by weight). (ppm) (wt%) (wt% KGew%)

1 33.0 2.19 156 86.8 x 28.5 2.44

2 - 33.0 2.19 71 79.5 20.4 1.52

Example 11:

An Illinois coal containing 105 ppm of elemental sulfur was crushed to a sieve fineness of 14 χ 150. Three samples were treated with 7.5 kilograms of iron pentacarbonyne per ton for 60 minutes at a temperature of about 175 to 195 ^° C. Sample No # 1 was not pretreated to remove sulfur but samples 2 and 3 were treated with hot toluene and rinsed with warm acetone prior to treatment with iron carbonyl. "The results of the comparison are shown in Table 11.

table 11: Temperature of 12: 190 - 195 ⁰ C 175 - 180 ⁰ C 190 - 195 ⁰ C analysis the rei , 9/2/2 # 5 a coal Lt-S (ppm) carbonyl treatment, Yield (weight) grayling Py ri (Ge \ , 68 _f 04, 96, 91 Sample- S ° 1 · 105 2 <1 3 Cl Analysis of the input material 69.6 74.2 66.6 20 15 12 25 co ro co co No. example

Lower Freeport coal with a sieve fineness of 14 χ 0 was treated for one hour with 16 kilograms of iron pentacarbonyl per tonne at a temperature of approximately 170 ^° C. Sample No. 1 was not pretreated to remove elemental sulfur, but samples 2 and 3 under the conditions for removal of a portion of the elemental sulfur listed in Table 12 as indicated. The results are given in Table 12, as well as the analysis of the coal used prior to any type of treatment.

table 12: · none 1 S ° (ppm) Yield CGew.%) ash Pyrite S Heated for 16 hours in air at 137 ⁰ C. 242 100/0 1.28 1/76 Sample No., preparation Steam 19 kg / t H ₁ 1700 ml / min at 130-140 ⁰ C for 15 min 242 56/9 22.5 1/85 feedstock 51 59/5 3.17 0/98 1 160 78/1 5.21 1/58 2 3

A 75 gram proline of Illinois Coal No. 6 ₇ mesh 14 140/2 / kg of elemental sulfur per tonne loaded into a rotating reactor was sublimed and allowed to react with the coal for 30 minutes at about 200 ° C. without gas flow »A corresponding 75 gram sample was not pretreated. * Each sample was thereafter treated with 7/5 kilograms of iron pentacarbonyl per tonne for 30 minutes at 190 to 195 ^° C. Table 7 (13) gives the relevant analysis of the activated carbon and the pure Charcoal from each sample «. ,

Table 13: of the starting material analysis of pure coal Pyrite S 0 / Pyrite sulfur % Yield wt% _e Ash 0 / 4/52 3/90 analysis 4/42 3/89 74/8 64/0 27/0 15/5 · Sample ash Sulfur 27.1 treated without pre- 30/4 treatment

Claims (2)

Berlin, _1Ο β 7 · 1978 GZ 52 702 18 Inventory test 1, Method of refining coal, treating raw coal with a metal-containing compound to increase the magnetic susceptibility of one or more impurities responsive to treatment with the metal-containing compound, thereby permitting removal of these impurities by means of magnetic separation characterized in that the coal is pretreated by being heated to at least one such temperature for at least a period of time such that a time-temperature ratio of D > K T-90 achieved or, "is exceeded, where D is the time the temperature in degrees Celsius and not less als'ca · 95 ⁰ C in hours and T, and where K is at least about, 0.5. 2 ", method according to item 1, characterized in that the metal-containing compound is an organic iron-containing compound« 3 * Method according to item 2, characterized in that the metal-containing compound has a sufficiently high vapor Berlin, the 1.0 * 7th 1978 GZ 52 702 18 ~ 26- 2 0 3 pressure - where iron is a constituent of the vapor «- in order to bring the iron into contact with the impurity at the reaction temperature * • 4o method according to any of the preceding items, characterized dadurchj that the metal-containing compound is one or, contains a plurality of compounds selected from the group consisting of ferrocene, ferrocene derivatives as well as _s Betadiketonverbindungen of iron _$. Dimethylferrocendioate, 1,1-bis-ferrocenedicarboxylic acid, ferric acetylacetonate, ferrous acetylacetonate, iron carbonyl, iron pentacarbonyl, nickel carbonyl, cobalt carbonyl, molybdenum carbonyI, tungsten carbonyl, and chromium carbonyl, are selected t ' Method according to item 1, characterized in that the metal-containing compound is an inorganic iron-containing compound. _E 6 »The method of item 4 _s characterized in that the treatment of Eisenpentkarbonyl within a temperature range of between about '150 ° 0 and 200 ⁰ C over a period of between approx» half and ca "is carried out for 4 hours 7 © Method according to one of the preceding points, characterized in that K is at least approximately * 5 and preferably at least approximately _β 2.5,. 8, method according to item 1, characterized in that the pretreatment at a temperature of at least 150 ⁰ C and preferably of at least 170 ⁰ G is performed » Berlin, the 10 "7" 1978 GZ 52 702 18 9 »Method according to item 1, characterized in that the duration of the pretreatment is at least one hour and preferably at least two hours *. Method according to item 1, characterized in that the pretreatment is carried out in the presence of one or more additives selected from nitrogen, steam, carbon monoxide, carbon dioxide, ammonia, methane, air, ethane, propane, butane and others gaseous hydrocarbon. selected from the group consisting of hydrogen compounds, 11. Method according to Item 10, characterized in that the additives are used in an amount of at least 1 ₉ 2 cubic meters of gaseous additives per hour per tonne of coal to be treated « 12 «Method according to one of the preceding points, characterized in that the impurities have pyrite and / or ash-forming minerals«, 13 «method according to any one of the preceding points, characterized in that elementary sulfur is removed from the impurities before increasing the magnetic capacity of the impurities, 14 · Process according to item 13, characterized in that the elemental sulfur is removed by solvent extraction « 15. The method according to item 14 »characterized in that the solvent is selected from the group consisting of carbon tetrachloride, toluene, acetone, methyl alcohol, ethyl alcohol, ether and liquid ammonia * Berlin, 10.7. 1978 GZ 52 702 18. 16 "Method according to item 13 _S, characterized in that the concentration of elemental sulfur in the coal following the removal of elemental sulfur is less than about 200 parts per million, preferably less than 50 parts per million and most preferably less than 10 parts per Million is » Process for upgrading coal containing impurities and elemental sulfur, the coal being treated with a metal-containing compound to increase the magnetic receptivity of one or more of the impurities responsive to treatment with the metal-containing compound, thereby removing these impurities by means of ma-. gnetscheiden, characterized in that before the treatment of the coal to increase the magnetic receptivity at least a portion of the elemental sulfur is removed *