CS215318B1 - Method of making the mortar from the fly ashes from the magnezite roasting - Google Patents

Abstract

The present invention provides a method for producing fly ash mortar of magnesite roasting dust. The essence of the process of making mortar rests in that they take on the dust from the roasting of magnesite eat ammonium formate and water, for the formation of basic magnesium formate as main product. As a mortar filler they use chemically indifferently granular inorganic or the mortar is combined with building binders. The importance of the mortar prepared according to the invention it is that it can be used for building construction blocks, casting mixes or during grouting work.

Description

The invention solves a method of producing mortar from dust from roasting magnesite.

The flue dust from industrial magnesite roasting, containing magnesium oxide as the main constituent, is a waste product in the manufacture of alkaline refractory construction materials. Their use for the production of building materials is prevented by a high content of impurities, in particular iron oxides, calcium oxide and silica. These impurities also prevent the upotrebeinie of flue dust for the production of febrile so-called. Sorel mortar, which is the basis of xylolite flooring.

The method of production of mortar from raw materials containing magnesium oxide as the main component is solved by the Czechoslovak author's certificate 178 thousand Θ74. Its substance is the reaction of caustic magnesite or calcined granular kysllčníkových magnesite industry waste with an aqueous solution of carboxylic acid of the composition _CnH2n-COOH, wherein n = 0, 1, 2, preferably formic or acetic acid.

SUMMARY OF THE INVENTION The present invention relates to a method of producing a magnesite roasting dust mortar, characterized in that 25 to 30% by weight of the magnesite roasting dusts are stored per 100 masses. parts by weight of calcium formate and 50 to 80 wt. parts of water to form alkaline magnesium formate as the main product. Chemically indifferently granular inorganic substances, e.g. quartz sand or ground limestone, or the mortar may be combined with building binders such as e.g. gypsum. Depending on the content of the individual components, the resulting mortar is initially liquid to plastic, later cured to hard and becomes resistant to the effects of water and carbon dioxide. The setting time can be influenced in a wide range from 1 hour. up to 48 hours on the one hand, by the ratio of the raw materials used, on the other hand, by the length and the manner of mixing the mixture, since the freshly prepared mortar is tlxotropic.

Unlike Sorel mortar, where high demands are placed on chemical purity, reactivity, and granulometric composition of magnesium oxide, magnesite flue dust blend has the most technically desirable properties such as controllability, solidity and low volume changes at high pollutant content. iron, calcium and silicon oxides. These properties make it possible to use it e.g. for the production of building blocks, for pouring mixtures for flooring of buildings or for grouting work.

Example 1

Per 100 wt. parts of magnesite roasting dust with a composition of 82,5% of magnesium oxide, 5,2% of iron oxide, 0,6% of iron oxide, 3,2% of calcium oxide and 1,9% of silicon dioxide (loss on ignition 6,4%) 30 wt. parts of calcium formate and 57 wt. parts of water. The resulting plastic material to which 50 wt. parts of quartz sand, as determined by the Vicato apparatus, start to set after 30 minutes. The cured product has a compressive strength of 18 MPa after 28 days.

Example 2

Per 100 wt. 28 parts by weight of the magnesite roasting dust composition as in Example 1 are parts. parts of calcium formate and 55 wt. parts of water. The resulting plastic to which 20 wt. parts of quartz sand and 20 wt. parts of ground limestone, as determined by the Vicato apparatus, start to set after 45 minutes. The cured product has a compressive strength of 15 MPa after 28 days.

Example 3

Per 100 wt. 30 parts by weight of dust of magnesite roasting composition as in Example 1 were collected. parts of calcium formate and 75 wt. parts of water. The resulting plastic to which 40 wt. parts of quartz sand and 40 wt. gypsum plaster, as determined by the Vicato apparatus, has a setting time of 40 minutes. The cured product has a lacquer strength of 20 MPa after 28 days.

Claims (2)

A process for the production of magnesite pulp dust from roasting dust, characterized in that per 100 wt. 30 to 30 wt. parts by weight of calcium formate and 50 to 80 wt. parts of water. INVENTION 2. A method according to claim 1, characterized in that it is added as a filler in an amount of up to 100% by weight. parts per 100 wt. parts of mortar of chemically indifferent inorganic granular substances, for example quartz sand or ground limestone, or construction binders such as gypsum.