CS195030B1 - Method of extraction of the ferro-ferric concentrate from the fly ash - Google Patents

Description

The invention relates to a method for obtaining a ferric-ferrous concentrate from fly ash resulting from the combustion of lignite or hard coal from mechanical and electrostatic precipitators or slag sites by a gravitational-magnetic method.

Processes for obtaining ferrous and ferric compounds are known in the art, comprising adjusting the combustion process in the furnace furnaces so as to maximize the amount of recoverable iron compounds. In other cases, the iron compounds are obtained by basic low-intensity magnetic dry or wet ash separation, or 3β performs a multiple purification of the magnetic separation product of the basic magnetic separation product. These known methods have many drawbacks. In the first case, the thermal-energy operation of the boiler room is often influenced by the fact that this operation is controlled to maximize the yield of recoverable iron compounds and only the second place is the thermal energy requirements of the operation, depending on the different types of coal burned.

Another method, that is, the immediate basic magnetic separation of fly ash, is economically disadvantageous because the entire amount of fly ash to be processed must pass through the basic magnetic separation, requiring considerable machinery capacity and increased energy requirements. Multiple purification is in turn time consuming because the basic magnetic separation product tends to have a low iron compound content.

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According to the invention, the above-mentioned drawbacks are eliminated by a method of recovering the ferric iron concentrate from fly ash produced from the combustion of lignite or hard coal from mechanical and electrostatic precipitators or from slags in a gravitational-magnetic manner.

Its essence lies in the fact that the fly ash is shattered into a usable ferrous-ferrous end in a shattering way and into a heavy and light fraction. The ash is freed from the slag by wet sieving.

The process according to the invention yields excellent ferrous-ferric concentrates with high metal content and yield, usable both in the tried and the powder state in the iron industry, in the original powder form as a weighting agent for hard-suspension treatment plants. 98% of the spherical shape of c is less than 0.017 to 0.255 mm. By the process according to the invention, it is possible to treat ashes with fluctuating iron content and with different granulometric composition with economic effect.

The process according to the invention is described in more detail below by means of several examples.

Example 1

2000 gr / ie. 100% weight / fly ash from the scrubbers were wet-shredded into an agitating sluice to form an iron-ferric concentrate containing 52% Fe, which was 11.57 g / i.

0.57% w / w to 910 g of heavy fraction (i.e. 45.50% w / w and 1078.43 g of light fraction (i.e. 53.93% w / w). Low intensity wet magnetic separation of the heavy fraction yielded 27.30 g / i. 3% w / w ferric-iron concentrate containing 65% Fe and

882.70 g / i.e. 42.50% w / w which still contained 0.50% Fe magnetite.

Example 2

200 kg / ie 100% by weight of the fly ash from the scrubbers were wet-divided into a shocking sluice into a ferric-ferrous concentrate of 3.30 kg / i. 1.65% w / w containing 60% Fe and at 65 kg / i. 32.5 # hmott to 131.70 kg / i.e. 65.8% wt / wt; Low-intensity wet magnetic separation yields 5 kg (i.e., 5.5% w / w) of ferric ferric concentrate with a content of 66 Fe and 60 kg of waste (i. 30% w / w which still contained 0.90% magnetite Fe.

Example 3

700 kg / ie 100% weight / fly ash from the scrubbers were wet-divided into a shocking sluice to an iron-ferric concentrate of 3.60 kg / i. 0.51% w / w containing 50% Fe and to 260 kg / i. 37% w / w and at 436.40 kg / i. 62.49% wt. Low intensity wet magnetic separation of the heavy fraction yields 13 kg / i. 1.1, 86% w / w ferric-iron concentrate with a content of 62% Fe 9 247 kg / ie. 35.14% w / w of waste which still contained 0.50% Fe magnetite.

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Claims (2)

1. A process for obtaining ferric ferric concentrate from fly ash formed from the combustion of lignite or hard coal from mechanical or electrostatic precipitators or from slags by gravity-magnetic method, characterized in that the fly ash on a shaking canal is separated into a usable ferric ferrous concentrate and heavy and light weight. 2. A method according to claim 1, characterized in that; the ash is freed from the slag by wet sieving.