SU1765131A1 - Method of artificial porous filler production - Google Patents

Abstract

Use: the manufacture of expanded clay from weakly plastered clay raw materials. The essence of the invention is to introduce an electrochemically oxidized tall oil pitch emulsion as an intumescent additive into clay oir. The electrochemical oxidation is carried out for 0.5-2 hours with the following parameters: current 1A, voltage 90 V. The oxidized emulsion is introduced into the mixing water and mixed with the clay raw material. Granulation and calcination are carried out using a plastic method according to the known claydite technology. Bulk density of filler is 169-182 kg / m3, strength 1.67-1.80 MPa, 1 dl., 2 tab.

Description

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The invention relates to the production of building materials and can be used to make expanded clay from weakly argillaceous clay raw materials.

A known method for producing a porous filler from a weakly pulverized raw material and an additive obtained by emulsifying tall oil pake and oil osprey in an aqueous solution of an alkaline stabilizer. The filler obtained in this way has a relatively high bulk density.

The closest to the proposed invention of the technical essence and the achieved effect is the method for the production of expanded clay, in which the clay raw material is mixed with the additive obtained by treating the tall pitch emulsion with sodium hygrochlorite.

The disadvantage of this method is the multistage process

the process of preparing the additive and the need to use a solution of sodium hypochlorite, which loses reactivity during storage.

The aforementioned reasons complicate the possibility of widespread use of tallcake-based additives in keramzite plants.

The aim of the invention is to reduce the bulk density of the aggregate.

The goal is achieved by using an emulsion of tall oil pitch, which has been electrochemically oxidized for 0.5 ... 2 hours with the following parameters as an intumescent additive in clay raw materials: current strength 1 A, voltage 90 V.

For the manufacture of the aggregate, low-fragrant fraternal loams are used. The chemical composition of clay rocks is presented in table 1.

VJ ON SL

WITH

Tall pitch is a by-product of sulphate-pulp production, which is formed during the distillation of tall oil.

Tall pitch contains, wt%: neutral substances 24-38, oxidized substances 12-29, resin acids 6-26, fatty acids 28-41. The acid number is 24–42 mg KOH / g, the saponification number is 49–155 mg KOH / g, and the softening temperature is 30–50 ° C.

Emulsification of tall oil pitch in an alkaline medium is used to convert a water-insoluble product to a process water-soluble state. In the process of emulsification in a 2% solution of NaOH, a partial cathode — Na + + 4Н20 4Н + + 40Н 4Н + + 4ё 2Н2 occurs.

At the anode, under the action of oxygen produced by an electrolytic method, the components of the pitch are oxidized, which leads to the appearance of additional oxygen-containing groups, which contribute to an increase in the total gassing during heat treatment. For example, when heated, carboxyl groups of carboxylic acids are decarboxylated according to the following scheme:

R

-Z

.0

h - R-№-CO f HE

The resulting gases intensify the redox processes occurring during calcination and accelerate the mass transfer to the pyroplastic state.

In the described electrochemical oxidation of tall pitch with oxygen, there are no significant destructive processes in the components of the pitch, which contributes to maintaining a wide temperature interval for burnout of the additive. The above processes together provide an increase in the intumescent effect and a decrease in the bulk density of the aggregate. The use of electrochemical oxidation does not cause coagulation of tall pitch, in contrast to treatment with sodium hypochlorite solution, in which the introduction of an additional electrolyte (NaCIO) contributes to the destruction of the hydrated shells of emulsified particles and causes their sticking.

saponification of fatty and resin acids with the formation of their sodium salts RCOONa.

The electrochemical oxidation of a tall pitch emulsion is carried out on an installation whose diagram is shown in the drawing.

When an electric current is passed through an aqueous solution of the salt of the active metal and an oxygen-containing acid (RCOONa), neither the cations nor the anions of the salt are discharged; instead, water ions are discharged: hydrogen ions at the cathode, and hydroxide ions at the anode.

Therefore, hydrogen is released at the cathode, and oxygen is produced at the anode. The electrolysis of an aqueous solution of RCOONa proceeds as follows:

Anode +

4Н20 4Н ++ 40Н 2НаО + 02

An example of the method of production.

Tall pitch is emulsified by heating in a 2% aqueous solution of an alkaline stabilizer (NaOH) and stirred for 2 ... 3 minutes to obtain a stable emulsion.

The mass ratio of organic

part of the emulsion and the 2% strength alkaline stabilizer solution is 1: 3. In terms of dry matter, the mass ratio of the alkaline stabilizer and the organic part of the emulsion is

1:17.

Electrochemical oxidation of the prepared emulsion is carried out at the facility, the scheme of which is shown in the drawing (for 0.5 ... 2 hours with the following

parameters: current 1 A, voltage 90 V), where 1 is a rectifier, 2 is a tank for oxidizing and restoring a tall pitch emulsion, 3 is an electronic bridge, 4 is a graphite anode; 5 - lead cathode; 6 magnetic stirrer.

The oxidized emulsion is introduced into the quenching water and mixed with the clay raw material until the components are evenly distributed. Granulation and roasting are carried out according to a known technology for obtaining expanded clay by plastic method.

Specific examples of the implementation of the method of manufacturing expanded clay and the characteristics of the properties of the aggregate are given

Table 2.

Examples No. 2,3,4 implementation of the method confirm the optimality of the selected

processing mode of the pitch emulsion and the composition of raw materials. When going beyond the boundary values, the purpose of the invention is not achieved.

According to the authors, the optimal method is the manufacture of the aggregate, in which the clay raw material is closed with water, into which a tall pitch emulsion is introduced in an amount of 0.9 ... 2.1 wt. 2 hours

The use of the proposed method for the production of expanded clay contributes not only to improve the quality of the aggregate and simplifies the technology of its manufacture, but also makes it possible to refuse the use of chlorine deposition in the process of modifying the pitch.

Fraternal quarry Airport

The content of basic oxides,% by weight on dry matter

 "". - ".-" IV "" m l "" "MW V" Mt "-" V "V -" ™

Si 0206CA120} Ti02 (Fe203 J Fed {CaO j MgO j MnO j

56.13 13.96 0.81 4.57 1.26 3.61 5.0 0.12 0.51

to „o

pzo5 i n.nins ..

total including org. J1

4.41 0.15 3.46 0.4

Clay consumption

raw materials, wt.% 99,682 99,04

Tall consumption

pitch, wt.% .0,30,9

Alkaline consumption

stabilizer, wt.% 0,018 0,053

Duration of electrochemical oxidation, min 1530

Characteristics of claydite in fractions of 5-20 mm according to GOST 9758-86:

Bulk density, kg / m3207

Strength, MPa 2.10

five

holding reagents, which improves working conditions.

Claims (1)

The invention of the method for producing an artificial porous aggregate by mixing a low-flowing clay raw material with a water-soluble additive obtained from a tall pitch emulsion, pelletizing and burning, in order to reduce the bulk density and simplify the manufacturing technology of the filler, electrochemical oxidation of a tall pitch emulsion for 0.5–2 h and introduced in an amount of 0.9–2.1 wt.% of the mass of clay raw material. Table 1 Table 2 195 1.94 212-265 2.10-2.31 t + g L BUT / / / i / J f V-4