Calcium Hypochlorite Tablets

　　Calcium hypochlorite tablets are a solid disinfectant mainly composed of calcium hypochlorite as the active ingredient.Common forms include tablets,granules,and other dosage forms.This type of product typically appears as a white or slightly gray solid with a characteristic odor similar to chlorine gas.As a refined product of bleaching powder,calcium hypochlorite tablets have become an important choice in modern water treatment and disinfection due to their high efficiency in sterilization,convenient use,and good stability.

　　1、Technical principles

　　Disinfection and sterilization mechanism:The disinfection ability of calcium hypochlorite tablets mainly comes from the hypochlorous acid generated after it dissolves in water.When the tablet is put into water,calcium hypochlorite reacts with carbon dioxide in water and air.The chemical equation is:Ca(ClO)₂+2H₂O+2CO₂=Ca(HCO∝)₂+2HClO.The generated hypochlorous acid molecules have a small volume and are electrically neutral,which can quickly penetrate the cell wall of microorganisms,enter the interior of the bacterial body,and undergo oxidation reactions with proteins and enzymes,disrupting the metabolic system of microorganisms and leading to their death.

　　It is worth noting that the bactericidal effect of hypochlorous acid is closely related to the pH value of water.When the pH value is below 6.5,the proportion of hypochlorous acid is higher;As the pH value increases,hypochlorous acid will gradually dissociate;When the pH value reaches 9.5-10.0,hypochlorous acid is basically ineffective.Calcium hypochlorite tablets usually make the aqueous solution alkaline after dissolution,and the pH value increases with concentration.Therefore,when preparing disinfectant solutions,attention should be paid to concentration control to ensure the best disinfection effect.

　　Stability principle:Compared to other chlorine containing disinfectants,calcium hypochlorite tablets have excellent stability.Pure calcium hypochlorite only decomposes 1.87%after being stored at room temperature for 210 days,making it more suitable for long-term storage and emergency reserves.The stability of the product benefits from the improvement of solid dosage forms and production processes.For example,Sinopec Jianghan Salt Chemical adopts advanced sodium production technology and DCS system control,producing high-quality and stable bleaching powder concentrate products.

　　To maintain this stability,calcium hypochlorite tablets need to be stored away from moisture,high temperatures,and light.Industry standards require that the effective chlorine content of bleaching powder tablets should not decrease by more than 20%within one year,and the decrease rate of tablets should not exceed 10%,and the effective chlorine content during the validity period should not be lower than the lower limit of the labeled content range.

　　2、Product advantages highlighted

　　High efficiency and broad-spectrum:Calcium hypochlorite has a killing effect on various microorganisms such as bacterial reproductive bodies,viruses,fungi,spores,etc.,and the action speed is fast.Experiments have shown that at the recommended concentration,the killing time for Staphylococcus aureus is only 1-2 minutes,much faster than alcohol(3-5 minutes)and iodine(5-10 minutes).

　　Stability and safety:The solid tablet form overcomes the disadvantage of easy decomposition of liquid sodium hypochlorite and can be stably stored for more than 12 months under cool and dry conditions.At the same time,the product meets the requirements of the"Disinfection Technical Specification"(2002 edition),has low skin irritation,and can be used for hand disinfection after dilution.

　　Economy and convenience:The cost of calcium hypochlorite tablets is only 60%-70%of that of chlorine containing disinfectant effervescent tablets,and the single dose is fixed(usually 1g or 5g),making it easy to add accurately.Compared to liquid disinfectants,there is no need to calculate the ratio concentration,reducing operational errors.

　　Environmental compatibility:The degradation products are calcium chloride and oxygen,which are non polluting to the environment.In sewage treatment plants,calcium hypochlorite can be used as a disinfectant and decolorizer,reducing COD(chemical oxygen demand)by 10%-15%while meeting the effluent residual chlorine standard.

　　3、Secure storage and transportation

　　Calcium hypochlorite tablets are hazardous chemicals with oxidizing and irritating properties,so special attention should be paid during storage and transportation:

　　Storage conditions:It should be stored in a cool,dry,and well ventilated clean place,avoiding direct sunlight and keeping away from sources of fire and heat.The storage temperature shall not exceed 30℃,and the relative humidity shall not exceed 80%.

　　Isolation requirement:Do not coexist with organic matter,acids,and reducing agents,as these substances may react violently with calcium hypochlorite.

　　Packaging specifications:The product is usually packaged in Class II plastic packaging drums lined with plastic bags.Common specifications include 1kg/2Kg/4Kg/10Kg/25Kg/40Kg/45Kg/50Kg,etc.

　　Transportation requirements:Measures such as sun protection and rain protection should be taken during transportation,and loading and unloading should avoid inversion and impact.

　　Packaging label:The packaging label of dangerous goods should comply with the provisions of"oxidizer"in GB190,ensuring that relevant personnel can identify and take appropriate protective measures during transportation and storage.

　　4、The use of calcium hypochlorite tablets must be strictly standardized:

　　Preparation for operation:Wear nitrile gloves,goggles,and protective clothing,operate in a well ventilated environment(air exchange≥10 times/hour),and stay away from acids,ammonium salts,and flammable materials.

　　Preparation method:Following the principle of"water first,medicine later",taking the preparation of 1%solution as an example,10g of calcium hypochlorite(effective chlorine 65%)is slowly added to 990ml of room temperature water,stirred for 5 minutes,and then allowed to stand for 10 minutes to obtain the supernatant.The solution needs to be prepared and used immediately,and after 24 hours,the effective chlorine decreases by 30%-40%.

　　Application points:Remove surface organic matter before disinfection,rinse food contact surfaces with clean water after disinfection,and immediately dry metal surfaces.Concentration adaptation scenarios:5-10mg/L for drinking water and 500-1000mg/L for medical surfaces.

　　Storage and emergency:Sealed and stored in a cool and dry place(temperature≤25℃,humidity≤75%).Block the area in case of leakage,dilute with water and collect;Rinse immediately for 15 minutes upon skin contact and seek medical attention.

　　Calcium hypochlorite tablets,as an efficient and broad-spectrum disinfectant,have become an indispensable disinfectant product in daily life and industrial production due to their high effective chlorine content,good stability,and convenient use.From disinfection of drinking water to surface treatment of objects,from medical and hygiene to industrial applications,calcium hypochlorite tablets have demonstrated excellent performance and wide applicability.