The method of extracting sulfur from sulfur concentrate

 

(57) Abstract:

Use: removing sulfur from sulfur concentrates sulfuric sludge formed during cleaning serovodorodsoderzhashchij gas oil industry. The inventive source of sulfur-containing raw material is melted in an aqueous solution of calcium chloride with a boiling point 5-15oC above the melting point of sulfur at a ratio of sulfur concentrate and solution of calcium chloride, equal to 1 g of the concentrate of 1-3 ml. 1 C.p. f-crystals, 1 Il., table 2.

The invention relates to methods for extracting sulfur from sulfur concentrates, in particular of sulphur sludge formed during interphase oxidative purification of hydrogen sulfide-containing gases in the oil industry.

Known extraction methods of removing sulfur from native ores [1]. They are based on its high solubility in many organic and inorganic solvents and inertness of these solvents in relation to the rock-forming materials. The crushed ore is treated with a solvent, while sulfur passes into solution, which is separated from the waste rock, and then from it emit sulfur in various ways.

One toxicity, explosion and fire hazards of solvents are an obstacle to the application of extraction techniques in the industry.

Closest to the proposed autoclave is a method of extracting sulfur from sulfur concentrate, in particular of sulphur sludge [2]. The method consists of heating the aqueous slurry of sulfur slurry to the melting point of sulfur. When this happens the coalescence of droplets of sulfur, separating sulfur from its gangue minerals and the precipitation of the liquid sulfur in the lower part of the reactor. To achieve the melting point of sulfur ( 120oC) heating the sulfur slurry is carried out in the autoclave at high pressure (10 ATM). To increase the selectivity of the process in the sulfur slurry add a number of chemicals: surfactants, Trilon B, hydrochloric acid, gasoline, etc.

The disadvantage of this method is ill-condition state embodies the resulting sulfur, the necessity of using expensive reagents, as well as the complexity of the equipment operating under high pressure.

The aim of the invention is to improve the quality of sulfur and simplification of the way.

This goal is achieved by the described method of extraction of sulfur from sulfur laulanie sulfur is conducted in aqueous solution of calcium chloride with a boiling point of 5 to 10oC above the melting point of sulfur at a ratio of sulfur concentrate and solution of calcium chloride is from 1:1 to 1:3 g/ml.

It is known that to increase the boiling point of water, you can either raise the pressure, or enter into the solution of the corresponding salt.

The maximum temperature, which is achieved by heating under normal conditions water suspension of sulphur sludge does not exceed 100oC, which is considerably below the melting point of sulfur. Additive to this suspension a salt of calcium chloride (to the density of 1.45-1,46 g/cm3) increases the boiling temperature of the water suspension of sulfur slurry to a temperature 5 to 10oC higher than the melting point of sulfur. Thus, without bringing the mixture to a boil (which prevents splashing), reach the melting point of sulfur. Later in this mixture, the origin of all those transformations, as in the autoclave process. However, unlike the prototype, this is achieved without creating a high pressure. In addition, part of the impurities contained in the sulphur sludge into solution of calcium chloride that provides increased, in comparison with the prototype, the purity sulfur. So, experimentally we have found that in a solution of chloride of calc the aqueous slurry solution of calcium chloride (CaCl2) contributes to the achievement of the melting point of sulfur at atmospheric pressure, as well as more pure sulfur.

The ratio of sulfuric sludge (g) to a solution of CaCl2(ml) in the range from 1:1 to 1:3 produces sulfur from the sulfur slurry.

Technological scheme of the method is shown in the drawing and comprises a container 1 for the dissolution of CaCl2in water, filter 2 for removing mechanical impurities from the solution of CaCl2the reactor 3, the carrier 4, the inlet pipes 5, 6, 7, respectively, for water, unfiltered and a filtered solution of CaCl2the pipe 8 to enter the sulfur slurry discharge piping: 9 - for the finished product, 10 for the secondary suspension.

The method is as follows.

In the load capacity 1 estimated number CaCl2and the pipe 5 serves of technical water, mix until dissolved CaCl2, measure the density and pH of the resulting solution. If the density is less 1,45 of 1.46 g/cm3add an additional amount of CaCl2; at pH values > 6,5 acidified with hydrochloric acid. Then, the solution on the pipe 6 serves to filter 2 for exemption from Mechanochemistry 120oC; then through the pipe 8 into the reactor 3 served with stirring in small portions the estimated amount of the sulfur slurry. The resulting suspension is brought to the melting point of sulfur and kept at this temperature for 0.5-1.5 h with gentle stirring. When this happens the coalescence of droplets of sulfur and settling them to the bottom of the reactor 3 in the form of liquid sulfur, which pipe 9 is devoted to the formation and consumer.

In the reactor 3 remains secondary (waste) suspension, which represents a suspension of insoluble sulfur compound slurry in a solution of CaCl2enriched soluble impurities from the sulfur slurry.

Secondary suspension can be used in two ways.

1. If the original ratio of sulfur slurry and solution of CaCl21:1 is quite thick suspension. The precipitation of the insoluble sulfur compound sludge in it is difficult. Such a suspension can be used as advocay liquid in the extraction of oil or thickening composition with the development of heterogeneous oil reservoirs, i.e., injected directly into the reservoir. For this purpose it is extracted from the reactor 3 through the pipeline 10 and is directed to the well.

2. When the ratio of ser is mentionne separation of insoluble impurities of sulphur slurry and the cleaning solution of CaCl2.

This solution can be used again in the process of extracting sulfur from sulfur slurry, mixing it with the new portion CaCl2to achieve the desired density. Technologically this exercise: measure the density of the used solution of CaCl2after deposition of insoluble impurities and added to the reactor 3 additional solution of CaCl2such density that after mixing with the used solution of CaCl2turned out the solution density of 1.45-1,46 g/cm3; next, apply the instructions above. When this secondary reaction of sulfur with a new portion of the sulfur slurry enters and remains in the reactor sludge. As shown by laboratory tests, it is possible to additionally extract about 4% sulfur.

The effectiveness of the proposed method was determined in laboratory conditions. Thus the following materials were used.

1. Sulphur sludge with the installation of desulphurization of gas. Composition (wt.%): sulfur 86,2; Trilon B-0.1; trisodium phosphate - 0,9; thiosulfate and sodium sulfate - 0,1; compounds of iron - 1,2; moisture - 11,5.

2. Calcium chloride technical, processed, manufactured, Sterlitamak, the Republic of Bashkortostan (GOST 450-77).

3 reflux, thermometer.

The results of these studies are presented in table. 1.

As can be seen from the table. 1, the maximum yield of sulfur is obtained when the ratio of sulphur slurry and solution of CaCl21:1(87,4%). Further decrease in the proportion of the solution of CaCl2leads to severe thickening of the resulting system, which complicates the process of coalescence and deposition of droplets of sulfur. The increase in the proportion of solution of CaCl2the ratio of sulfuric sludge: a solution of CaCl2leads to simplification of the process of coalescence of the droplets of sulfur by reducing the viscosity of the suspension, however, significantly increase the cost of the reagent (CaCl2). Thus, the optimum ratio is from 1:1 to 1:3.

Obtained by the proposed method, the sulfur was analyzed according to GOST 127-76 variety 9900 "technical Sulfur", approved and put into effect 01.06.90, PL. 2 shows the data obtained.

Received autoclaved fusion (prototype) sulfur did not meet the state standard, the content of iron in it was of 0.75%.

The advantage of the proposed method in comparison with the prototype is that it allows you to produce sulphur higher quality using readily available and cheap is the use of calcium chloride solution, the melting of sulfur at a temperature above the temperature of its melting point by 5 - 15oC, characterized in that the sulfur melting lead in the environment of calcium chloride at a ratio of sulfur concentrate and solution of calcium chloride, equal to 1 g of the concentrate 1 - 3 ml.

2. The method according to p. 1, characterized in that the feedstock uses sulfuric sludge from the purification of hydrogen sulfide-containing gases in the oil industry.

 

Same patents:

The invention relates to the field of hydrometallurgy, in particular to a method of processing serosorting material released by sulfuric acid autoclave-oxidative leaching of sulfide raw materials, obtaining sulfur and sulfide concentrates sent to further processing

FIELD: chemistry.

SUBSTANCE: method for separation of the elemental sulphur and sulphide concentrate from the intermediate products of the sulphide concentrates hydrometallurgy processing includes sulphur-sulphide flotation of the intermediate original pulp in order to separate the sulphur and sulphides from intermediate oxide components with forming of the sulphur-sulphide concentrate. Then the autoclave disintegration of the sulphur-sulphide concentrate pulp is carried out in the presence of reagent - sulphide hydrophilisator and at the temperature higher than melting point of the elemental sulphur. After that the sulphur flotation is carried out in order to separate the disintegrated pulp into sulphur and sulphide concentrates. Before the sulphur-sulphide and sulphur flotations the pulp undergoes the additive agitation with the reagents, the disintegration is carried out at the temperature 140-150C.

EFFECT: effective separation of the sulphur and sulphide concentrates.

5 cl, 3 dwg, 1 tbl

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