SK281351B6 - Process for the preparation of agglomerated additives for building materials - Google Patents

Abstract

Granulated additive material for construction material is prepd. by mixing with a liq. to form a suspension, and then spray drying in a fluidised bed drying method to produce granules.

Description

Technical field

The invention relates to a process for the production of cementitious or lime-bonded granulated building materials, such as concrete liquefiers, paint enhancers, air pore formers, inorganic pigment dyes, strength enhancers or the like, which are contemplated for dry mixing. liquid or pasty building materials.

BACKGROUND OF THE INVENTION

In the concrete industry, various additives are used to change the properties and color of the concrete. By mixing certain additives in liquid paints, the ability to thicken concrete can be increased in order to increase the compressive strength and uniform compression of the concrete products. There is an economic advantage associated with reducing the cement content. Better dispersibility of the cement size also causes a more closed surface. Finally, the increased plasticity of the concrete promotes faster filling of the molds and a long service life of the stone molds due to low wear on their walls. Thus, by using various additives and combinations of substances, it is possible to achieve certain application-oriented properties of the concrete and the products made thereof.

However, when combining paints, coloring aids and technologically usable additives, it is necessary to take into account the compatibility of these substances. These additives often form chemically unstable solutions and also by additional admixing of dispersants and chemical stabilizers the problem of sustained storage stability of the liquid is increased.

The use of inorganic and organic pigments has already been known in the construction industry for dyeing concrete products, and in particular pigments based on inorganic dye pigments have proven to be practical. These pigments are added to the concrete mixtures in powder form. Due to the good dispersibility, a complete homogeneous distribution of the pigment powder in the concrete mixture takes place within a few minutes.

The disadvantage of using powder pigments is that they do not have good flowability, often clump and clump when stored, and due to the fine separability of the pigment powder used, more or less large contamination of the plant, plant and environment must be expected.

It is known to avoid these disadvantages by using pigment granules as coloring agents. Such a process is described in DE 36 19 363, wherein a pigment granulate is a spray-dried mixture of water, pigment and binder. Manganese oxides, iron oxides, organic pigments and / or carbon as well as a mixture of individual pigments are used as pigment. As binders which act as dispersing aids in the concrete, they may be: alkylbenzenesulfonate, alkylnaphthalenesulfonate, ligninsulfonate, sulfated polyglycol ether, melanin-formaldehyde condensates, naphthalene-formaldehyde condensates, gluconic acid, low-molecular-weight maleic acid copolymers, partially esterified. The proportion of pigments is two to six percent by weight.

The main disadvantage of spray granulation drying is that a hollow space is formed in the center of the granule, due to the technical process. As a result, the strength of the granule is less, so that the granules can be destroyed during transport and storage and the proportion of particles smaller than 0.1 mm can be so large that the flowability of the material can be reduced.

It is known from DE 41 03 531 that, in order to reduce the proportion of particles smaller than 0.1 mm, the granules are spray-dried preferably for 15 minutes to 2 hours, at a temperature of up to 300 degrees Celsius, granulated in drums, worms or rotary plates.

The high cost of regranulation considerably increases the cost of production of the pigment granules.

Accordingly, there is a task of providing an inexpensive process for the production of an additive which is characterized by good manufacturing stability, easy to use in the mixing process of building materials, and which alters the properties of the building material in a desirable manner without substantially harming other parameters of the building material.

SUMMARY OF THE INVENTION

The above drawbacks are largely eliminated by the method of producing granulated cement-lime-based building additive materials such as concrete liquefier, paint enhancer, air pore builder, inorganic pigment dyes, strength components or the like that are contemplated for mixing into dry, liquid or pasty building materials. The principle of the invention is that the additive (s) is dispersed in the liquid or mixed into an initial suspension. This starting slurry is sprayed onto the seed of its own starting material by the following fluidized-bed granulation drying process and granulated into a building material miscible intermediate.

In a preferred embodiment, the initial additive suspension is 20 to 60 wt. % solids and, in the case of inorganic coloring pigments, based on a solids content of 2 to 6 wt. binders, sprayed into fine droplets onto the embryos found in the bed of the fluidized bed granulation dryer with material sorting process, at the inlet air temperatures of the heat carrier at 150 to 250 ° C are granulated into granules of an average of 0.1 to 1, 25 mm with a humidity of 0.5 to 5% and are continuously distributed by the screening process.

In this case, products in pure form or in a mixture thereof, suitable as concrete liquefiers, are used as a binder for granulating inorganic coloring pigments.

The vent temperature of the fluidized bed granulation drying is 30 to 40 ° C.

The advantages of the process according to the invention for the production of cement and lime-bound building materials such as concrete liquefier, paint enhancer, air-pore-forming agent, inorganic pigment-based dyes, strength-enhancing components and the like are that by granulation drying With the fluidized bed, a fine-grained end product is produced which is dust-free and which has good pneumatic conveying behavior. Granular colorants and the like can be added to the concrete mixture in exact amounts. In addition, the granules dissolve rapidly in the concrete mixture. The measurements indicate that the dissolution of the granulates and the homogeneous distribution of the additive in the concrete mixture occur in less than 100 seconds. Concrete does not create fibrous dirt and nests with paint. *

A further advantage of the process according to the invention is that no hollow granules are formed which are produced by spray drying. Due to the strength and high bulk density of the granulates produced, adequate transport, storage and handling will prevent damage or destruction of the granules and thus the generation of dust.

Preferably, inorganic coloring pigments based on metal and carbon oxides, preferably iron oxides, which are slurried with water and binder, are preferably used as starting materials for the production of the granular colorant for coloring building materials. The starting colorant suspension comprises 40 to 60% solids content, to solids content, 2 to 6% binder.

DETAILED DESCRIPTION OF THE INVENTION

The process according to the invention is explained in more detail on the basis of an exemplary embodiment thereof.

In order to produce a granulated dye for coloring building materials, it is 50 wt. % dry red iron oxide (Bayferrox 130), 3 wt. % lignin sulfonate and 1 wt. Optapix AC 95 with the addition of water produced the starting substance for the dye, the binder additive data refer to the solids content.

This initial slurry is sprayed into fine droplets onto the embryos which are located on the bed of the fluidized bed granulation dryer with a material sorting process. At the inlet air temperatures of the heat carrier at 160 degrees Celsius, granules are formed and the fluidized bed is dried. The exhaust air temperature is 35 degrees Celsius.

The finished granules are discharged by a vortex layer granulation dryer through the screening process. The moisture content of the granules produced is 1% and the grain size is between 0.1 and 1.0 mm. The granules are dust-free and have a high bulk density. When added to the concrete mixer, the granules were completely dissolved and homogeneously distributed in the concrete mixture within 100 seconds.

Claims (5)

PATENT CLAIMS A process for the production of granulated additives for cement and lime-bound building materials, such as, for example, a concrete liquefier, a color enhancer, a pore-forming agent, inorganic pigment-based dyes, strength enhancers or the like intended to be mixed into dry, liquid or pasty building materials, characterized in that the additive (s) is dispersed or mixed into the starting suspension in the liquid, the starting suspension being sprayed onto the seed of its own starting material and granulated into an intermediate by the following fluidized-bed granulation drying process. into the building material. 2. A process according to claim 1, wherein the initial suspension of the additive with 20 to 60 wt. % solids and, in the case of inorganic coloring pigments, based on a solids content of 2 to 6 wt. binder, it is sprayed into fine droplets on its own embryos, which are located in the bed of a fluidized bed granulating dryer with a material sorting process, at the temperatures of the air of the heat carrier at 150 to 250 ° C are granulated into granules in an average of 0.1 to 1 25 mm with a humidity of 0.5 to 5% and are continuously distributed by the screening process. Method according to claim 1 or 2, characterized in that products in pure form or in a mixture thereof, suitable as concrete liquefiers, are used as a binder for the granulation of inorganic coloring pigments. The method according to claims 1 to 3, characterized in that the vent temperature of the fluidized bed granulation drying is 30 to 40 ° C. Process according to one of Claims 1 to 4, characterized in that the additive or admixture is an inorganic pigment based on metal and / or carbon oxides.