KR20100096339A - Cement having harmonic ph in environment - Google Patents

Abstract

PURPOSE: Environment-friendly cement is provided to secure the environment-friendly pH of the cement by adding thiourea, urea and sodium thiosulfate(hypo) for neutralizing the strong alkalinity of the cement. CONSTITUTION: Environment-friendly cement capable of controlling the pH contains 1wt% of either thiourea or urea for controlling the strong alkalinity of the cement, and sodium thiosulfate(hypo) for maintaining the pH of the cement, for 99wt% of cement. Carbon and active alumina is contained in the cement to remove the hexavalent chrome generation.

Description

Cement having harmonic pH in environment

The present invention relates to an environmentally friendly cement, and more particularly, by adding thiourea, urea, and crystalline sodium sulphate (hypo) to the cement to neutralize the strong alkalinity of the cement, thereby improving the environmentally friendly pH. It relates to an environmentally friendly cement that can be adjusted to have a pH control.

Cement, which is widely used today, is generally referred to as Portland Cement. In the broader sense, cement means Inorganic Cementing Material that hardens when kneaded with water.

Portland cement is a powder obtained by mixing a sufficient amount of raw materials containing lime, silica, alumina, and iron oxide as main components in an appropriate ratio, and adding a portion of gypsum to a sintered clinker.

It is widely used in various construction and civil engineering materials, such as buildings, roads, bridges, blocks, sleepers, and poles, using concrete molded by mixing aggregates such as gravel and sand with water in such Portland cement.

However, when kneading a mixture of sand or gravel crushed stone with the clinker constituents of Portland cement, it loses fluidity and condenses after a while, and then various toxic substances are generated by chemical reaction during the curing process. These toxic substances not only deteriorate the health of residents living in concrete buildings, but also cause damage to animals and plants, causing serious environmental pollution.

In addition, Portland cement products absorb moisture in the air and calcium hydroxide produced by hydration combines with carbon dioxide in the air to form lime carbonate. It is caused to be coated with, and about 6.0% of magnesium oxide (MgO) contained in the cement dissolves chromium contained in the ore, releasing hexavalent chromium toxicity to the outside.

Thus, the method for producing a pollution-free Portland cement of Korean Patent No. 871393 (2008.11.25), which not only neutralizes the toxicity of cement but also suppresses the release of hexavalent chromium, which is a harmful substance having a strong influence on living organisms. Presented by the applicant of the present invention.

In this prior art, calcium chloride (CaCl ₂ ), sugar carbide, activated alumina (Al ₂ O ₂ ) as additives are mixed with cement to absorb toxic substances and moisture to remove cement odors and toxic substances, hexavalent chromium A technique is disclosed that enables the production of.

Cement, on the other hand, is said to be made of "alkali," usually about 11-12 pH. This is because the reinforcing bars are not easily corroded.

However, in the case of cement-containing moldings having strong alkalinity, even after a considerable period of time, strong alkaline properties of about -12H 11-12 have been shown, and in such "strong alkali" waters, there is a problem that the fish cannot live in the environment.

Therefore, the object of the present invention was devised in view of the above-mentioned point, by controlling the pH of the cement to neutralize the strong alkali properties of the cement and to remove the toxic substances to have a safe and environmentally friendly pH to survive aquatic life The present invention provides an environmentally friendly cement which can control pH to make cement moldings.

The environmentally friendly cement which can control the pH of the present invention for achieving the above object is determined to maintain at least one of the geoelements and urea for the pH control of the cement having strong alkali, and to maintain the adjusted initial pH state. Sodium sulfate (hypo) is 1% by weight to 99% by weight of cement Includes environmentally friendly cement with added pH control.

The environmentally friendly cement which can control the pH of the present invention, by adding geoelements, urea and sodium crystalline sodium sulphate (hypo) to the cement to neutralize the cement having strong alkali to about 7.5 to maintain the state In addition, it provides environmentally friendly cement products that can survive aquatic insects and freshwater fish, and can produce pollution-free cement products that can be harmless to humans or animals or plants even when used in riverside blocks or apartment buildings.

Hereinafter, preferred embodiments of the present invention will be described in detail.

To general cement cement, geourea, urea, and crystalline sodium sulfite (Hypo) are added at a constant mixing ratio.

Geourea is an organic compound containing a sulfur atom instead of an oxygen atom of urea. The molecular formula is (NH ₂ ) ₂ CS. It is generally used as a starting material in the manufacture of catalysts, pesticides, surfactants, corrosion inhibitors, photography fixatives, thermosetting resins, textile treatments, specific dyes and drugs, and there are few commercial uses. Here, the chemicals react with lime, silica, alumina, gypsum, etc. contained in Portland cement to remove harmful substances and to neutralize the strong alkalinity of the cement. In particular, the pH control value is changed depending on the amount of geoelements added, so if you add a large amount should be added to the appropriate amount. Applicants have found the optimum amount of addition through several experiments. It is possible to control the cement of cement by adding geoelements, but since geoelements are expensive compounds, they are added together with relatively inexpensive elements with the same chemical properties as geoelements in consideration of competitiveness in production.

Urea is a substance with the chemical formula CO (NH ₂ ) _{2. It} has no color or smell and is a highly polar substance that produces columnar crystals and is soluble in water. Hydrolysis of urea neutralizes alkalinity by controlling the pH of cement by releasing ionic products from non-ionic substrates according to the following formula:

Here, the urea used is for agriculture, which is decomposed into ammonium carbonate by the enzyme urease of microorganisms in the soil, and the decomposed ammonia is adsorbed in the soil and contributes to plant growth. Nitrogen in urea is not a protein but is used in ruminants (bovines and sheep), and is an important source of protein for animals and is used in large quantities in the manufacture of urea-formaldehyde resins and the synthesis of barbiturates as well as fertilizers. It is used for medicinal inos for the production of paints, dye adhesives, sweeteners, scavenger, petroleum and oil and fat separation and purification.

Urease is a urease that breaks down urea into ammonia and carbon dioxide.

Sodium Thiosulfate (Sodium Thiosulfate) is also known as hypo, which is used in photographic adhesives, oil bleach, pharmaceutical analysis reagents, leather, dye synthesis, reducing agents, heavy metal poisoning. Here, the crystallized sodium geosulphate (Hypo) is to stabilize and disinfect the disinfectant toxic substance of cement, and to fix the initial pH controlled by the geoelements and urea to maintain the pH even after a considerable period of time. To 99% by weight of cement, the sum of geourea, urea, and crystallized sodium sulfite (hypo) is added at a blending ratio of 1% by weight.

Meanwhile, carbon (carbon) and activated alumina are additionally added to the cement to which geourea, urea, and crystalline sodium sulfite (hypo) are added to prevent hexavalent chromium from being dissolved and released.

Here, activated alumina (Al ₂ O ₂ ) blocks the root cause of dissolving about 6.0% of magnesium oxide contained in cement raw materials by dissolving chromium contained in sand or gravel stone by dehumidification and catalysis of gas. Let's do it.

Here, the blending ratio is shown in Table 1 below.

Product Name Weight ratio (% by weight) Portland Cement 98.4 Geo element       0.8 Element   0.16 Crystalline sodium sulfate (Hypo)   0.04 Carbon       0.2 Activated alumina       0.4 system     100

Sand is added to the cement mixed in the above mixing ratio according to the ratio of product properties to produce cement products. Since the chemical properties of the geoelement and the urea are the same, the same pH control can be achieved by adding only at least one of them or changing the weight ratio thereof. The result of measuring the pH of the cement-containing moldings thus made is shown in Table 2 below, and the cement-containing moldings were left together with the stones of the general river in order to see the change in the pH over time after manufacture, and then measured by sampling. It is.

additive Weight ratio
(weight%) Early
JH 1 month later
JH 6 months later
JH 12 months later
JH Geo element
Element
Crystalline Sodium Sulphate 0.8
0.16
0.04
7.5
7.5
7.5
7.5 Geo element
Element
Crystalline Sodium Sulphate 0.9
0.21
0.04
6
6
6
6 Geo element
Element
Crystalline Sodium Sulphate 0.7
0.11
0.04
8.5
8.5
8.5
8.5

As shown in Table 2 above, the pH varies depending on the amount of geoelements and the addition of urea, and it can be seen that the pH immediately after preparation is maintained by adding sodium hexasulfate (hypo).

Therefore, the cement of the present invention has an environmentally friendly GH which can survive aquatic insects and freshwater fish by neutralizing the strong alkali and toxic substances inherent in the cement to provide the conditions necessary for the survival of the organism.

As such, the environmental factors of the geoelements are ground water when released into the soil, are not expected to biodegrade when released into the water and can be removed by dry deposition to a moderate extent when released into the air. Environmental toxicity is harmful to aquatic plants and may cause long-term side effects in the aquatic environment. However, the chemicals of limestone, silica, alumina, and gypsum in Portland cement can dilute and remove mutually dangerous substances. Strong alkalinity neutralizes, neutralizes by pH control and provides the conditions necessary for the survival of living organisms so that fish can live, noxious toxic substances are extinguished, and aquatic organisms do not interfere at all, and there is no bacterial infectious disease. In the case of geoelements, there is little commercial use, but the emergence of environmentally friendly cement processed products to expand the cage of Portland cement by the present invention is very encouraging.

Claims (3)

At least one of the urea and urea for the pH control of the strongly alkaline cement, and the sodium sulphite (hypo) is added in a blending ratio of 1% by weight to 99% by weight of cement to maintain the controlled initial pH state. Environmentally friendly cement with pH control. The environmentally friendly cement of claim 1, wherein carbon and activated alumina are further added to remove hexavalent chromium from the cement. The geourea, urea, crystalline sodium geosulfite (hypo), carbon, and activated alumina are 0.8 wt%, 0.16 wt%, 0.04 wt%, 0.2 wt%, and 0.4 wt%, respectively, based on 98.4 wt% of cement. Environmentally friendly cement which can be adjusted at the blending ratio of%.