SU1678791A1 - Method for lime preparation - Google Patents

Abstract

This invention relates to the building materials industry. The aim of the invention is to increase productivity and reduce fuel consumption. Prepare an aqueous solution of 0.1 kg DMB (calculated on dry matter) and 60 kg of water. The solution is fed to a scrubber, where it is contacted with gases from the rotary kiln. Gas temperature is 220 ° C. The resulting aqueous suspension, containing 0.3 kg of dust solids (0.5% of the solid phase), is fed into a mash and mixed with 150 kg of chalk to obtain a slurry with a moisture content of 38%. From the chatter, the sludge is fed to the consumable sludge pool, then fired in a rotary kiln. The lime obtained in the roasting process is cooled. Lime activity 94.3%. Capacity increased by 29%, fuel consumption 0.2690 kg. 3 tab.

Description

The invention relates to the building materials industry, primarily to the technology of lime production.

The aim of the invention is to increase productivity and reduce fuel consumption.

For the production of lime, chalk is used, the chemical composition of which is given in Table 1.

The method is carried out as follows.

Example 1. An aqueous solution is prepared from 0.1 kg of SDB (calculated on dry matter) and 60 kg of water. The solution is fed to a scrubber, where it is contacted with gases from the rotary kiln. Temperaura gas 220 ° C. The resulting aqueous suspension containing 0.3 kg of dust solids (0.5% of the solid phase) is fed into a mash and mixed with 150 kg of chalk to obtain a slurry with a moisture content of 38%. From the chatter, the sludge is fed to the consumable sludge pool, then

firing in a rotary kiln. The lime obtained in the roasting process is cooled. Lime has an activity of 94.3%.

Example 2. A solution of lignosulphonates of Example 1 is prepared. The solution is fed to a scrubber, where it is contacted with gases from the rotary kiln. An aqueous suspension is formed which contains 1.8 kg (3.0%) of solids. Sludge humidity 36.0%, lime activity 95.8%

Example 3. A slurry of example 1 and 2 was prepared to a solid phase concentration of 5.0%. Similarly, sludge is prepared with a moisture content of 36.8%. Calcination in a rotary kiln produces lime with an activity of 95.3%.

Example 4. A suspension according to Example 1 is prepared with a solids concentration of 0.3%. Using the suspension, get chalky slime moisture 38.7%. The fluidity of 70 mm, the activity of lime 92,8%.

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Example 5. Suspension is prepared, reaching a solid phase concentration of 5.8%. Using the suspension, get chalky slime humidity of 40.6% with a yield strength of 70 mm. The activity of the resulting lime 93,0%.

Table 2 shows the technological parameters of the process of obtaining lime depending on the concentration of the solid phase of the suspension, which is formed during the contact interaction of the RDB solution with the exhaust gases,

As can be seen from Table 2, the effective use of the suspension obtained by contacting the gases coming from the rotating nets with an aqueous solution of lignosulfonates is achieved when the concentration of the solid phase in the suspension is within 0.5-5% (examples 1-3 ). Lower concentrations lead to a reduction in lime quality (example 4). Exceeding these limits leads to an increase in the moisture content of the sludge, which requires an increase in fuel consumption for the evaporation of additional moisture.

Table 3 presents the results of the implementation of the proposed and known methods.

The lime obtained by the proposed method has an activity of 94.3-95.3%. In the preparation of sludge, no

commodity product, and powdered waste production.

The production of lime from natural raw materials according to a known method requires the return of 29% of lime to the technological cycle, as a result, the sludge thickens, which leads to an increase in its moisture content and, consequently, fuel consumption,

A comparison of the known and proposed methods shows that the proposed method eliminates the use of marketable lime, as a result, the furnace capacity increases by 29%, and the fuel consumption in the process decreases by 21.1%.

Claims (1)

Invention Formula The method of obtaining lime, which includes preparation of carbonate raw material sludge with lime-containing component and lignosulfonates, subsequent calcination in a rotary kiln, characterized in that, to increase productivity and reduce fuel consumption, lime lime with a solids concentration of 0.5 is used as lime-containing component - 5.0%, which is obtained by contacting the gases from the rotary kiln with an aqueous solution of lignosulfonates. Table 1 Table 2 Process indicators (per 1 kg of marketable lime) Quantity, kg: lime (activity 75%), introduced into the sludge Cao SDB (calculated on dry matter) The moisture content of chalk sludge,% Conditional fuel consumption, kg Lime activity,% Table 3 Lime according to the method Famous 0.29 0.22 0.002 51.5 0.341 93.2