SU1252331A1 - Peat briquette - Google Patents

Description

This invention relates to the production of a briquetted fuel suitable for use in the metallurgical industry and the household industry.

The purpose of the invention is to increase the compressive strength and reduce water absorption.

In tab. 1 shows the properties of screenings of charcoal, petroleum coke and coal.

From tab. Figure 1 shows that the basic properties of screenings of charcoal and petroleum coke are close to each other and are noticeably different from the properties of hard coal.

Charcoal screenings (with a particle size of up to 10 mm) are waste obtained in the preparation of coal for use as a reducing agent in the electrothermal production of silicon. Small fractions of petroleum coke (up to 8–10 mm) in a significant amount (yield 40–50% of the total

masses of petroleum coke) are formed in the process-25 product enters the process of producing petroleum coke on delayed coking units. In addition, small fractions (screenings) of charcoal and petroleum coke are formed during their transportation, which is determined by their low mechanical strength.

The use of these screenings in the composition of the peat briquette allows to obtain high-quality finished product.

on the one hand, the thermal performance of the briquette is significantly improved: the heat of combustion and carbon content increase, the humidity and ash content decrease; on the other hand, mechanical strength increases and water absorption decreases. The first circumstance is directly related to the composition of screenings, the second is determined by their nature. Since screenings have low compressive strength and high porosity, co-pressing them with peat provides significant benefits. With the usual pressing pressure of 100 MPa, the particles of screenings, having destroyed, not only form new active surfaces, but also increase the total area of contacts. In this case, peat goes into a fluid state. It becomes possible to prepare high-quality briquette without a special binder.

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The development of the surface and the increase in the number of contacts of the additional filler (siftings) and the binder (peat) leads to an increase in the physical and intermolecular interaction forces in the briquette, i.e. increase contact strength. The deeper penetration of the binder into the pores of the “filler particles” results in an increase in the adhesion forces; O hardens the briquette and at the same time its water absorption decreases.

PRI me R. The components of the briquetted charge are: wet milled peat, screenings of 0– tO mm charcoal and petroleum coke, cameous coal O — 2 mm.

The composition of carbon materials is given in table. 2

Before briquetting, 20 milling peat is dried in a pipe dryer to a moisture content of 19.8Z. Peat is served by a scraper conveyor and a receiving bunker to a dry conveyor and then to a screen. The heating furnace, the flue gases of which, after being diluted with air to 600-700 seconds, is a drying agent. Peat size less than 6 mm poured

into the bunker, which is a container for both the pressed raw material and the process fuel. The feed to the dryer and the fuel to the furnace are produced by two plate feeders of variable capacity. With a grinding fan, the coolant is sucked from the furnace and transported together with peat through a dryer into precipitation cyclones with simultaneous grinding of peat. From cyclones through the intermediate bunker and the flasher the peat is poured by gravity into the feed bin and from it into the press for briquetting.

Carbonaceous materials (screenings of charcoal and petroleum coke) in the initial state are metered by the feeder from the feed bin to the path for supplying dried peat to the press. Thus, the components of the mixture are mixed in a certain ratio and then pressed.

The production of briquettes is carried out on an industrial stamp press B-8232 with a capacity of 4 t / h of peat briquettes. Extractive briquettes with a specific pressure of 100 MPa under the influence of the impact force of the press are transferred by continuous tape through metal

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who tray in the finished product bunker. When falling from a tray into a hopper, a tape of pressed material 170x70 mm in size breaks up into separate briquettes with a height of 50 - 110 mm.

The quality of the briquettes is estimated as solid fuel and reducing agent for the heat of combustion, mechanical abrasion resistance in the drum and water absorption.

The main results of the research of briquettes of the proposed composition in comparison with the known are given in table.

As can be seen from the data given in table. 3, the proposed briquette consisting of 50–90Z peat and 10–50Z screenings of charcoal, petroleum coke, or a mixture of them, has higher mechanical strength and a lower water absorption rate compared to the known peat briquette with the addition of 20 40Z stone coal (optimal, ihta).

The positive impact of the proposed carbonaceous materials (screenings of charcoal and petroleum coke) on the quality of peat briquette becomes noticeable when they are introduced in an amount of 10Z or more by weight of the briquette.

Small amounts of screenings from the angle of oodized materials (less than tOZ)

Woody tree

coal 8.2-90.0 0.8-5.2

, Oil screenings

l

second peat

woody

Content, Z per working mass

iaBr

Carbon 40.5

79.4

Ash

Moisture

13.7

3.5

19.8

9.3

0

$

0

It is practically difficult to set and evenly distribute in the volume of peat. It turned out that some of the briquettes made did not contain carbonaceous materials. Another part of the briquettes is characterized by uneven Skoplenk, ;;, and, fluctuation of the particles of carbon additives, which leads to a sharp decrease in the strength of the peat briquette. The introduction of small additions of carbonaceous materials to the peat briquette is not economically profitable due to the relatively large capital expenditures on the installation and maintenance of the equipment of the receiving-airing unit. In addition, a peat briquette containing less than 10% of charcoal and petroleum coke screenings is characterized by lower values of heat of combustion and carbon content than peat briquettes. Therefore, it is not technologically and economically feasible to introduce carbonaceous materials into the peat briquette in quantities less than 10Z.

With an increase in the content in the briquette of charcoal and petroleum coke screenings above 50Z, its mechanical strength decreases significantly and the water absorption is unacceptably increased (up to 1282).

Table I

29500-32000

0.7-1.060-80

.0.3-0,5

Table 2

Heat of combustion, kJ / kg

iaBr

Ash

Moisture

13.7

19.8

10,050

3.5

9.3

30800

Continuation of table 2

Claims (1)

TORFOBRIKET, including peat and carbonaceous material, characterized in that, in order to increase compressive strength and reduce water absorption, it contains screenings of charcoal, petroleum coke or their mixture as carbon material in the following ratio of ingredients, May 2: Peat 50-90 Screenings of charcoal, petroleum coke or mixtures thereof 10-50