UA122950C2 - METHOD OF PRODUCTION OF BINDING MATERIALS FROM METALLURGICAL SLAG MELTS - Google Patents

Abstract

The invention relates to the utilization of waste metallurgical production - slag in the molten state to obtain binders suitable for Portland cement. Method for production of binders from metallurgical slag melts by crushing and enrichment with crushed solid additives of molten slag jet. Crushing into particles of a stream of molten slag, purified from metal-containing components, enriching them with crushed solid additives is carried out in a cylindrical mixing channel simultaneously by interacting the slag jet with a two-phase turbulent flow of gas suspension (air with solid particles enriched in the shaft furnace at a rate that is lower than the two-phase flow rate in the cylindrical mixing channel and cooled in a fluidized bed created in the shaft furnace. The proposed method allows to obtain high-quality binders from slag melts, expanding the list of recycled slags (blast furnace, steel, etc.), to reduce energy consumption.

Description

The invention relates to the utilization of metallurgical production waste - slag in a molten state to obtain binding materials corresponding to Portland cement (PC) in terms of their properties.

A known method (1| of production of binding material (cement) from fire-liquid metallurgical slag with crushed solid additives with heating of the melt by burning fuel in a converter with nozzles for blowing heated air into the melt and introducing fuel through the nozzles together with air, which in the opinion the author of this method should increase the intensity and completeness of fuel combustion, improve the heat exchange between fuel combustion products and the melt and, contributing to more intense mixing of the melt, accelerate the dissolution of additives in it.

The disadvantage of the method is the following. According to this method, the melt is heated with already introduced additives, which coagulate the entire mass of slag and additives (limestone), the mass fraction of which exceeds the mass of slag, lowering its temperature, making it difficult to obtain clinker and requiring additional burning of fuel, which makes obtaining clinker by this method high energy consumption.

A known prototype method (2) for obtaining Portland cement clinker from blast furnace slag, which involves introducing hot air into a mine furnace with a slag melt, enriching and crushing the melt into particles, enriching them with solid additives and heating by burning fuel, which is carried out sequentially along the height of the mine furnace: on the upper level - hot air and or high-temperature gases leaving the furnace; on the middle - crushed solid additives (limestone) together with hot air at an upward angle; on the lower level - fuel together with hot air also at an upward angle.

The disadvantage of the method is the following. To obtain high-quality PS clinker with a standard modulus of hydraulic activity in the range of 1.7-2.4 |З| according to this method, an addition of limestone in the range of 65-75 95 is necessary, depending on the chemical composition of blast furnace slag. The introduction of such an amount of additive into the slag melt requires high energy costs to maintain the temperature in the mine furnace at least 1400 "C for the clinker formation reactions, which leads to the complication of the technological process and the increase in the cost of the final product - the binding material (clinker PC).

A disadvantage of the method is also the possibility of obtaining binding material only from blast furnace slag.

The invention is based on the task of improving the method of production of binder materials from metallurgical slag melts, in which, due to changing the sequence of actions, an increase in the quality of the obtained binder is achieved using slag melts of various metallurgical cycles (blast furnace, steelmaking), with an additional reduction in energy consumption .

To solve the problem in the method of production of binder materials from metallurgical slag melts, which includes crushing and enriching the stream of molten slag with crushed solid additives, according to the invention, crushing the slag stream cleaned of metal-containing components into particles and enriching them with crushed solid additives is carried out simultaneously in the cylindrical mixing channel by interaction of the slag jet with the two-phase turbulent flow of the gas suspension (air with solid particles of the enrichment additive), with the formation of enriched granules, which are introduced into the water cooling chamber of the furnace at a speed lower than the speed of the two-phase flow in the cylindrical mixing channel, and the obtained granules are cooled in fluidized air layer created in a mine furnace.

In addition, the parameters of the effect on the slag stream by the two-phase flow of the gas suspension (phase pressure and velocity) are regulated by changing the consumption of the solid phase (enrichment additive) and the consumption of the energy-bearing phase (air) at a constant ratio of the mass fraction of the enrichment

BO additives td to the mass fraction of slag, equal to td/tsh-0.15-0.2.

The method is implemented in the device, the scheme of which is presented in the figure, where 1 - slag melt accumulator, 2 - inclined slag tray, C - mixing cylindrical channel, 4 - accelerating cylindrical section of the injected two-phase flow of gas suspension, 5 - enrichment additive hopper (PID/PID clinker ), 6 - enrichment additive dispenser, 7 - nozzle for supplying compressed air (working flow), 8 - injector mixer chamber, 9 - conical (diverging) nozzle of channel 3, 10 - cooling chamber of the mine furnace, 11 - blast air jets, which ensure the formation of an ascending fluidized layer (flow).

The method in this device is carried out as follows: in the accumulator 1, the slag melt is cleaned of metal-containing components by precipitation and heated to a temperature of 1450-15007 along the inclined slag tray 2 in a uniform stream is fed into the mixing cylindrical channel 3, where from the accelerating cylindrical section 4 to the slag stream affected by a turbulent two-phase flow consisting of an air phase and particles (-80 μm) of a solid enriching phase - portland cement (PC), which is 0.15-0.2 (15-20 95) of slag |4, table. 3.45).

The two-phase flow of the gas suspension is obtained by ejecting the enrichment additive from the hopper 5 through the dispenser b and supplying the energy carrier (compressed air) - a high-speed working flow from the nozzle 7 of the injector, capturing the enrichment additive in the mixing chamber 8, which has a lower pressure in front of the accelerating cylindrical section 4 . The kinetic energy of the working flow is partially transferred to the injected flow - the solid phase.

In chamber 8, the working and injected flows are mixed. The newly formed two-phase gas suspension (air with solid particles of the enrichment additive) enters the acceleration section 4 for discharge at an increased speed into the mixing cylindrical channel C for interaction with the slag jet. Since in the acceleration section 4 with a length of about I1-150 mm, the velocities of the phases (air and solid particles) equalize within 260-270 m/s |4, s. 49) before discharge into channel 3, the effect of crushing the slag jet by a high-speed two-phase flow will be higher than under the influence of a single-phase flow (2Y1. At the same time as the slag jet is crushed, the formed slag droplets are enriched with solid particles of the two-phase flow additive, which stick to or are introduced inside drops of slag due to the kinetic energy of the particles of the enrichment additive, i.e. the simultaneous crushing of the slag stream and the enrichment of the formed drops takes place to the cooling chamber 10 of the mine furnace.

Further discharge in the form of a flow of heated and enriched granules into the cooling chamber 10 occurs through a conical expansion nozzle 9, which reduces the speed of particle emission into the chamber 10 relative to the speed of the two-phase flow in the channel 3. Air nozzles 11 form a fluidized flow that slows down the fall of particles due to levitation in a fluidized layer of air. The cooling chamber 10 and the retardation of the fall of particles in the fluidized bed accelerate the cooling process of the particles, which helps to reduce the size of the furnace in height.

From the enriched and cooled slag particles to a temperature that excludes their sintering during unloading and their subsequent fine grinding, a binding material is obtained, which in terms of its hydraulic properties corresponds to the M 400 PID.

In the proposed method, in contrast to the method I2| additional energy costs in the mine furnace are excluded - there is no burning of fuel.

In addition, the use of the slag melt accumulator allows removing metal-containing components from the slag and expanding the list of processed slags (blast, steelmaking, etc.).

Sources of information: 1. Author's certificate of the USSR Mo 106149, СО4В 7/44, declared on November 9, 1955 under Mo 548/154710. 2. Pat. Mo 111327 of Ukraine, С0О4В 7/14, declared on April 11, 2016, date of publication 10.11.2016, Bull. Mo. 21. 3. Kolokolnikov V.S. Production of cement. - M.: Higher School, 1970. - P. 42-46. 4. Kravchenko V.P. Dissertation "Establishment of parameters of jet grinding during processing and enrichment of blast furnace slags". Dnipropetrovsk. 2014. - 210 p.

Claims (2)

FORMULA OF THE INVENTION 1. The method of production of binding materials from metallurgical slag melts, which includes crushing and enrichment with crushed solid additives of the jet of molten slag, which is characterized by the fact that the crushing into particles of the jet of slag, cleaned of metal-containing components, and their enrichment with crushed solid additives are carried out simultaneously in cylindrical mixing channel by interaction of the slag jet with the turbulent two-phase flow of gas suspension - a mixture of air and solid particles of the enrichment additive, with the formation of enriched granules, which are introduced into the water cooling chamber of the mine furnace at a speed lower than the speed of the turbulent two-phase flow in the cylindrical mixing channel, and cool the obtained granules in a fluidized air layer created in a mine furnace. 2. The method according to claim 1, which differs in that the parameters of the effect on the slag stream by the two-phase flow of gas suspension (phase pressure and velocity) are regulated by changing the consumption of the solid phase (enrichment additive) and the consumption of the energy-bearing phase (air) with a constant ratio of the mass fraction of the enrichment additive (td) to the mass fraction of slag (ty), equal to td/tsh--0.15- or 0.2.