SU1678622A1 - Composition for cleaning working surfaces - Google Patents

Abstract

The invention relates to construction materials, namely the cleaning of metal surfaces from hardened cement stone. The purpose of the invention is to reduce material costs. Composition for cleaning metal surfaces of equipment contains the following components, wt.%: 25-35% aqueous solution of orthophosphoric acid 99.9-99.95, zinc oxide 0.05-0.1. After the composition has been applied to the metal surface with residues of hardened cement, the latter are destroyed and a layer of insoluble phosphate of zinc is formed on the metal surface, which ensures the corrosion resistance of the metal. 1 tab.

Description

The invention relates to building materials, namely, compositions for breaking hardened cement, and can be used to destroy packed hardened cement residue during its transportation in metal tanks, containers, auto cement trucks, on specialized vessels.

The purpose of the invention is to reduce material costs.

The composition for cleaning metal surfaces from cement stone includes the following components, wt%: 25-35% orthophosphoric acid aqueous solution 99.9-99.95; zinc oxide 0.05-0.1.

The composition is applied to dirty surfaces of the container. The composition destroys the hardened cement, and a layer of insoluble phosphate of zinc, which has high protective properties and isolates the metal surface from the external environment, heals the corrosion resistance of the metal, forms on the surface of the metal container.

Example. In order to prepare 1000 g of a composition containing 20% orthophosphoric acid, 710 g of water is added to 290 g of the latter (the product is a solution of 70% concentration) and stirred. Then to 999 g of a 20% aqueous solution of orthophosphoric acid with stirring, add 1 g of zinc oxide (0.1%). The resulting mixture is stirred until complete dissolution. Similarly, different versions of the composition are prepared, different in content of orthophosphoric acid and oxide zinc.

In order to separate the time of the destruction of the hardened cement, the samples "Ј

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The coping stones are weighed, placed in 250 ml beakers with a volume of 0.05-0.1% based on the mass of the orthophosphoric acid solution and filled with a composition containing a solution of 20-40% orthophosphoric acid with zinc oxide.

The amount of phosphoric acid is taken from the calculation: to dissolve 1 kg of hardened cement, 175 g of 35% orthophosphoric acid are needed. The rate of dissolution of the cement stone is determined by the gravimetric method.

The degree of protection (SZ) of corrosion inhibitors (the ability of the inhibitor to protect steel from corrosion) is determined by the formula

cz yo%

where KI is the corrosion rate of steel in an aggressive environment without an inhibitor;

K.2 - corrosion rate of steel in the same medium, but additionally containing a corrosion inhibitor.

In parallel on steel samples Art. 3, measuring 4x4x3 cm, determine the corrosion rate by the gravimetric method. For this purpose, the samples are placed in chemical glasses, in which the process of dissolving the cement stone takes place.

The results of the dissolution of the cement stone, the corrosion rate of steel and the degree of protection depending on the amount of inhibitor and the concentration of orthophosphoric acid are presented in the table,

The test results show that the maximum dissolution rate of cement stone with a minimum corrosion rate and maximum degree of protection is achieved after 48 hours at 18-20 ° C with a composition containing 25-35% phosphoric acid solution and zinc oxide in an amount of 0.05-0 , 1% relative to the mass of the orthophosphoric acid solution. FORUMUA and EOBREYTNI

A composition for cleaning metal surfaces from cement stone, including an aqueous solution of orthophosphoric acid and a metal corrosion inhibitor, is intended to contain 25–35% aqueous solution of phosphoric acid to reduce material costs. as a corrosion inhibitor - zinc oxide in the following ratio of components, May. %:

25-35% water

orthophosphoric solution

acids 99.9-99.95

Zinc Oxide0.05-0.1

Claims (1)

Claim Composition for cleaning metal surfaces from cement stone, including an orthophosphoric acid aqueous solution and a metal corrosion inhibitor, characterized in that, in order to reduce material costs, it contains a 25-35% orthophosphoric acid aqueous solution, and zinc oxide as a corrosion inhibitor in the following ratio of components, May. %: 25-35% aqueous phosphoric acid solution 99.9-99.95 Zinc oxide 0.05-0.1 Example The concentration of Hj PO, in solutions, X The amount of pink oxide, X in relation to the mass of the solution N _? P0u The degree of protection ^With E "% The residue after dissolution of the cement stone, X, with exposure, h 5 10 fifteen 25 35 68 94 37 74 62 57 49 26 96 S5 72. 60 54 47 25 96 85 73 61 53 46 24 95 88 75 63 56 48 27 95 79 69 61 39 19 8 96 76 65 5s 35 16 5 96 75 65 58 34 fifteen 6 95 80 68 .60 38 19 8 96 78 67 62 39 19 7 97 74 65 57 35 fifteen 5 97 75 66 57 34 fifteen 5 96 77 68 61 38 20 6 96 77 68 60 37 20 8 97 74 65 56 .34 16 5 97 74 65 57 34 fifteen 4 97 78 69 59 36 19 7 95 84 77 70 58 41 19 97 82 74 67 55 38 16 97 82 74 67 55 38 16 95 87 32 69 59 40 20 Corrosion rate, g / m ^A h 0.01 0.006 0.005 0.007 0.01 0.005 0.005 0.005 0.01 0.006 0.006 0.007 0.01 0.006 0.007 0.006 0.01 0.007 0.007 0.007