A Chloride metal salt water-repellent agent is a colored liquid prepared by mixing calcium chloride, aluminum chloride, and other metal salts with water in a particular proportion.
After the Chloride metal salt water-repellent agent is mixed into concrete (mortar), during the hydration and hardening process of cement, it can react with cement and water to generate complex salts, fill the gaps in concrete and mortar, and improve the compactness and impermeability of concrete. To play the role of water-repellent and anti-seepage, this agent has the functions of quick setting, early strength, pressure resistance, waterproofing, anti-seepage, and anti-freeze. It can be used for waterproofing and impermeability on roofs, basements, underground moisture-proof layers, swimming pools, and water tanks. The dosage is about 5% of the cement dosage.
1.Ferric chloride water-repellent agent
A ferric chloride water-repellent agent is a dark brown, strong, acidic liquid generated by a chemical reaction of iron oxide scale, iron powder, and industrial hydrochloric acid at average temperature in a particular proportion. Ferric chloride water-repellent agent can be used to prepare water-repellent concrete and mortar which is suitable for rigid waterproofing in industrial and civil building basements, pools, water towers, and equipment foundations, as well as other brick masonry, concrete, and reinforced concrete projects in underground and humid environments, and waterproofing and plugging. It can be used to prepare mortar and concrete that prevents gasoline penetration. According to relevant regulations that limit the scope of use of chlorine salts, the use of ferric chloride water-repellent concrete is prohibited for projects that come into contact with DC power supply, prestressed reinforced concrete, and critical thin-walled structures. A ferric chloride water-repellent agent is suitable for underwater structures and large-volume concrete projects with no or few reinforcements.
The preparation method of the ferric chloride water-repellent agent is as follows.
(1) Preparation of ferric chloride water-repellent agent using iron oxide scale as raw material.
This type of ferric chloride water-repellent agent is a ferric chloride solution generated by a chemical reaction between rolled steel and industrial hydrochloric acid in an appropriate proportion at standard temperature (>10°C).
a. Components
The iron oxide sheet has the following components: Fe₂O₃ (iron oxide), FeO (ferrous oxide), Fe₃O₄ (ferric oxide). If there is any oil or dirt on the oxide scale, it should be cleaned and crushed through a 3mm mesh;
Hydrochloric acid (HCl) can be industrial ones, with a specific gravity of 1.15 to 1.19;
The main component of aluminum sulfate [Al₂ (SO₄)₃] is Al₂ (SO₄)3 · 18H₂O. A small amount of aluminum sulfate is added to the ferric chloride solution. Its primary function is to react with Ca(OH)₂ in the cement to generate Al(OH )₃ colloid, and in addition, it creates calcium sulfoaluminate to expand and increase the compactness of concrete and mortar. Aluminum sulfate can be industrial hydrated aluminum sulfate with an aluminum sulfate content <5%;
brown iron oxide should be steel-making oxygen-blown steel ash and red iron powder.
b. Preparation method
The mixing ratio of iron oxide water-repellent agent is iron oxide scale: iron powder: hydrochloric acid: aluminum sulfate = 80:20:200:12.
Put the iron powder into the ceramic jar, add half of the hydrochloric acid used, and stir it with an air pump or machine for 15 minutes to allow it to react fully. If manual stirring is used, the time should be extended to 1h to 1.5h. After dissolving, add the iron oxide scale and the remaining half of the hydrochloric acid, stir mechanically for 45 minutes to 60 minutes, and then react naturally for 3 to 4 hours until the solution becomes thick soy sauce, the ferric chloride solution. Let the solution stand for 2 hours. ~3h, pour out the clear liquid, remove impurities and undissolved matter, leave it for 12h, add industrial aluminum sulfate accounting for 5% of the total ferric chloride solution, stir thoroughly to dissolve, and then use completely.
c. Finished product requirements
The relative density of ferric chloride water-repellent agent should be greater than 1.4, the ratio of ferric chloride should be in the range of 1:1 to 1.3 (mass ratio), and its practical content should be no less than 400g/L; The pH value of the water-repellent agent solution is 1 to 2; the aluminum sulfate content accounts for about 5% of the weight of the ferric chloride solution.
(2) Preparation of ferric chloride water-repellent agent using pyrite slag as raw material
This type of ferric chloride water-repellent agent is a ferric chloride solution that chemically reacts at room temperature with industrial waste from sulfuric acid plants and industrial hydrochloric acid, with an appropriate amount of alum added.
a. Components
Pyrite slag is an industrial waste from the manufacturing of sulfuric acid. Its main component is iron oxide and a small amount of iron, silicon oxide, alumina, calcium oxide, and sulfur. When preparing a ferric chloride water-repellent agent, choose one with a higher iron oxide content. , slag with low silica content needs to be dried before preparation, with a moisture content of <2%, and impurities are removed through sieving; cutting waste from mechanical processing can be used for iron filings; industrial alum is generally used as alum; hydrochloric acid and aluminum sulfate are the exact Requirements for preparing ferric chloride water-repellent agent made of iron oxide scale.
b. Preparation method
Prepare the materials according to the quality of pyrite slag: hydrochloric acid = 1:2~3, pour the hydrochloric acid into the ceramic cylinder, and then slowly pour the mixture of pyrite slag and iron filings accounting for 5%~10% of the mass of the hydrochloric acid into the hydrochloric acid. , stir continuously for about 3h, then stir every 0.5h, clarify after 24h, and measure its relative density. When the relative density is >1.3, add alum or aluminum sulfate with about 10% of the solution mass and continue stirring until it is completely dissolved, that is, finished products.
The finished product requirements are the same as those of the ferric chloride water-repellent agent using iron oxide scale as a raw material.
