What is calcium hydroxide?

氫氧化鈣是一種白色粉末狀固體。化學式Ca(OH)2，俗稱熟石灰、消石灰，加入水后，呈上下兩層，上層水溶液稱作澄清石灰水，下層懸濁液稱作石灰乳或石灰漿。上層清液澄清石灰水可以檢驗二氧化碳，下層渾濁液體石灰乳是一種建筑材料。氫氧化鈣是一種二元中強堿(氫氧化鈣在中學階段被認為是強堿，而實際上其在水中不能完全電離，因此在大學教材中被認為是中強堿)，具有堿的通性，對外表，織物有腐蝕作用。

Calcium hydroxide is a white powdery solid. The chemical formula Ca (OH) 2, commonly known as hydrated lime and hydrated lime, forms two layers after adding water. The upper aqueous solution is called clarified lime water, and the lower suspension is called lime milk or lime slurry. The clear lime water in the upper layer can test carbon dioxide, and the turbid liquid lime milk in the lower layer is a kind of building material. Calcium hydroxide is a binary medium strong alkali (calcium hydroxide is considered as a strong alkali in middle school, but in fact it cannot be completely ionized in water, so it is considered as a medium strong alkali in College Textbooks). It has the universality of alkali and has a corrosive effect on the appearance and fabric.

氫氧化鈣的用途有那些?氫氧化鈣應用領域

What are the uses of calcium hydroxide? Application field of calcium hydroxide

氫氧化鈣在工業中有廣泛的應用。它是常用的建筑材料，也用作劑和化工原料等。

Calcium hydroxide is widely used in industry. It is a commonly used building material. It is also used as fungicide and chemical raw materials.

1、可作生產碳酸鈣的原料。

1. It can be used as raw material for the production of calcium carbonate.

2、氫氧化鈣屬堿性，因而可以用于降低土壤的酸性，從而起到改良土壤結構的作用。農藥中的波爾多液正是利用石灰乳(溶于水的氫氧化鈣)和硫酸銅水溶液按照一定的比例配制而出的。冬天，樹木過冬防蟲，樹木根部以上涂80公分的石灰漿。

2. Calcium hydroxide is alkaline, so it can be used to reduce the acidity of soil and improve the soil structure. Bordeaux liquid in pesticides is prepared by using lime milk (calcium hydroxide dissolved in water) and copper sulfate aqueous solution in a certain proportion. Trees with more than 80 cm of lime in winter.

3、品主要用于生產環氧氯丙烷、環氧丙烷。

3. High quality products are mainly used to produce epichlorohydrin and propylene oxide.

4、可用在橡膠、石油化工添加劑中，如石油工業加在潤滑油中,可防止結焦、油泥沉積、中和防腐。

4. It can be used in rubber and petrochemical additives. For example, it can be added in lubricating oil in petroleum industry to prevent coking, sludge deposition, neutralization and corrosion prevention.

5、用于制取漂白粉、漂粉精、劑、制酸劑、收斂劑、硬水軟化劑、土壤酸性防止劑、脫毛劑、緩沖劑、中和劑、固化劑等。

5. It is used to prepare bleaching powder, bleaching powder essence, disinfectant, acid making agent, astringent, hard water softener, soil acid inhibitor, depilant, buffer, neutralizer, curing agent, etc.

6、氫氧化鈣和空氣中二氧化碳還會發生反應從而形成難溶于水的碳酸鈣。制糖工業生產中，先利用氫氧化鈣中和糖漿中的酸，然后通入二氧化碳和剩余氫氧化鈣反應生成沉淀物被過濾出去，以此減少糖的酸味。

6. Calcium hydroxide also reacts with carbon dioxide in the air to form calcium carbonate that is insoluble in water. In the sugar industry, calcium hydroxide is first used to neutralize the acid in the syrup, and then carbon dioxide is introduced to react with the remaining calcium hydroxide to form precipitates, which are filtered out, so as to reduce the sour taste of sugar.

氫氧化鈣在各領域的用途

Application of calcium hydroxide in various fields

一、氫氧化鈣污水處理方面的具體應用

1、 Specific application of calcium hydroxide in sewage treatment

1、氫氧化鈣用在廢水中可以中和廢水中的游離酸。

1. Calcium hydroxide used in wastewater can neutralize free acid in wastewater.

2、氫氧化鈣用在廢水中可以中和廢水中的酸性鹽。

2. Calcium hydroxide used in wastewater can neutralize the acid salt in wastewater.

3、氫氧化鈣用在廢水中，其中氫氧化鈣中的氫氧根離子可以與金屬離子反應生產不溶于水的沉淀物。

3. Calcium hydroxide is used in wastewater, in which hydroxyl ions in calcium hydroxide can react with metal ions to produce water-insoluble sediments.

4、氫氧化鈣用在廢水中，可以調節廢水的PH值堿性，這樣可以更好的使金屬氫氧化物沉淀。

4. When calcium hydroxide is used in wastewater, the pH value of wastewater can be adjusted to alkaline, which can better precipitate metal hydroxide.

二、氫氧化鈣農業方面的具體應用

2、 Specific application of calcium hydroxide in agriculture

1、農業上用它降低土壤酸性，改良土壤結構; 2、農藥波爾多液是用石灰乳和硫酸銅水溶液按一定比例配制的。這種用于果樹和蔬菜的天藍色粘稠的懸濁液農藥，是通過其中的銅元素來消滅病蟲害的。

1. In agriculture, it is used to reduce soil acidity and improve soil structure; 2. The pesticide Bordeaux solution is prepared with lime milk and copper sulfate aqueous solution in a certain proportion. This sky blue viscous suspension pesticide for fruit trees and vegetables is used to eliminate diseases and pests through copper.

其中不僅利用了氫氧化鈣能與硫酸銅反應的性質，也利用了氫氧化鈣微溶于水的特點使藥液成粘稠性，有利于藥液在植物枝葉上附著。另外氫氧化鈣與空氣中的二氧化碳反應生成微溶于水的碳酸鈣，也有利于藥液附著于植物表面一段時間不被雨水沖掉。 3、冬天，樹木過冬防蟲，樹木根部以上涂80公分的石灰漿。

It not only makes use of the nature that calcium hydroxide can react with copper sulfate, but also makes use of the characteristics that calcium hydroxide is slightly soluble in water to make the drug solution viscous, which is conducive to the attachment of the drug solution to plant branches and leaves. In addition, calcium hydroxide reacts with carbon dioxide in the air to produce calcium carbonate slightly soluble in water, which is also conducive to the solution adhering to the plant surface for a period of time without being washed away by rain. 3. In winter, trees are protected against insects in winter, and 80 cm lime slurry is applied above the roots of trees.