Dramatic drug practitioners

1, approved by special personnel, received by special personnel, and kept by special personnel.

2. Wear work clothes, protective glasses and gloves.

3. Two people. Double lock, two people can be unlocked at the same time.

4. First-in, first-out principle, accurate registration when issuing: measurement of reagents, issuing time and handlers.

5.a stands for highly toxic chemicals explicitly prohibited by the state. B stands for pesticide banned by the state.

6. Sodium cyanide (NaCN) is a white crystalline powder, which is highly toxic. In humid air, it will emit bitter almond flavor due to moisture absorption.

Soluble in water, the aqueous solution is strongly alkaline.

Hydrolysis equation:

H2O+CN(-) = (reversible symbol) HCN+OH(-) Usage: This product can be used for gold and silver extraction from ores (hydrometallurgy), electroplating (electroplating solution), metal quenching, pesticide manufacturing, organic synthetic chemicals and other industries. Occupational poisoning is mainly caused by inhaling dust from respiratory tract or steam formed by sodium cyanide during heat treatment. Sodium cyanide is also absorbed through the skin and digestive tract. During World War II, it was widely used by Nazi Germany to produce hydrocyanic acid in concentration camps and transported to gas chambers disguised as bathhouses through pipelines, killing many Jews.

1. Danger

Sodium cyanide of various specifications is a highly toxic chemical with the hazard code of 81001; The lethal dose of sodium cyanide is 0.1-0.3g. When mixed with acid, potassium chlorate, nitrite and nitrate, or exposed to humid air for a long time, it is easy to produce highly toxic, flammable and explosive HCN gas. When the concentration of HCN in the air is 20ppm, people will have poisoning symptoms and die a few hours later.

The toxic hazards of sodium cyanide and HCN (hydrogen cyanide) are classified as Grade I (extremely dangerous).

2. First aid for cyanide poisoning

2. 1. Poisoning is mainly inhalation of dust or hydrogen cyanide gas in respiratory tract. It can also be absorbed through the skin and digestive tract to cause poisoning. People can die by taking 0.06 g hydrocyanic acid and 0. 1-0.3 g sodium cyanide orally.

2.2. Inhale sodium cyanide dust or hydrogen cyanide gas, leave the scene immediately, move to fresh air, and detoxify with antidote. If the poisoning is particularly serious, people will be rescued by cardiopulmonary resuscitation. When you touch the sodium cyanide dust or splash the sodium cyanide solution, you should take off the contaminated clothes in time and rinse your skin with clear water. 3% boric acid solution can be used to clean the injured area of skin burn.

2.3. Application of antidote

In case of sodium cyanide poisoning, 3% sodium nitrite 10- 15ml was added to 40ml of 25% glucose solution for intravenous slow injection. Immediately after injection, 25-50 ml of 50% sodium thiosulfate was slowly injected intravenously with the same needle and the same part. If sodium cyanide is taken by mistake, 10% sodium thiosulfate solution or 1:2000 potassium permanganate solution can be used for gastric lavage, and an appropriate amount of ferrous sulfate solution can be taken orally after gastric lavage.

3. Explosion and fire control measures

Sodium cyanide itself will not burn, but it is easy to produce highly toxic, flammable and explosive hydrogen cyanide gas, which reacts strongly with nitrate and nitrite and is in danger of explosion. In case of fire during storage, transportation and use, water, yellow sand and dry powder fire extinguishers can be used to extinguish other items. It is strictly forbidden to rush into the scene of sodium cyanide fire to prevent a large number of poisoning caused by the flow of toxic water. It is forbidden to use acid-base or carbon tetrachloride fire extinguishers, and firefighters should wear gas masks before entering the fire.

4. Treatment of sodium cyanide leakage

When sodium cyanide leaks (liquid) or falls into the water, the field personnel should check the isolated accident leakage site in time under the condition of protecting their own safety, and give an alarm to the relevant leaders and "1 19", the local environmental protection department and the public security traffic police department. In case of transportation, alarm should be given to the local emergency rescue department or "1 19", and the alarm content should be the time and place of the accident, the name of the chemical, the amount of leakage and the degree of danger; Whether there are casualties and poisoning, the name and telephone number of the alarm person. At the same time, according to the situation of sodium cyanide leakage and diffusion and the areas involved, a warning zone was set up to implement traffic control on the main roads leading to the accident site. Except for fire fighting and emergency response personnel, other personnel are prohibited from entering the warning area, and irrelevant personnel should be evacuated quickly. Personal protective equipment and gas mask should be worn during handling, and corresponding monitoring measures should be taken. Ground residues should be neutralized and removed with 5 times of soda solution and buried deep in the soil.

5. Operation precautions and storage

When operating, the operator must wear overalls, gloves, masks and gas masks to prevent sodium cyanide from directly contacting the skin or inhaling sodium cyanide dust. After the work is finished, you must repeatedly wash with clean water or 5% sodium thiosulfate aqueous solution, bathe and put on clean clothes. Eating, drinking and smoking are strictly prohibited during work.

In operation, because sodium cyanide is easy to hydrolyze (ammonia and sodium formate are generated from aqueous solution above 60℃), the temperature of sodium cyanide aqueous solution should not be too high in the process of using sodium cyanide, so as to avoid sodium formate affecting the use efficiency. In addition, with the increase of standing time, the content of sodium cyanide in a certain concentration of sodium cyanide aqueous solution will decrease due to hydrolysis, which should be remembered and paid attention to during operation.

During the storage and use of sodium cyanide, remember not to put it in one place with acid, nitrite, nitrate and other substances, or expose sodium cyanide to acidic environment, which will reduce the product quality and use effect; Nor should it be stored in a humid environment and piled up in the open air for a long time. It should be stored in a ventilated and dry place, with a special warehouse or counter and double locks. During storage, it should be inspected and maintained regularly, the temperature and humidity of the storage place should be controlled, and corresponding ventilation or humidity reduction measures should be taken. Storage places should be equipped with corresponding exhaust ports. 6. Protective measures.

In the process of production, use, handling and storage of sodium cyanide, in order to protect operators from injury, process equipment should be strictly sealed to prevent leakage, and the automation level should be improved to reduce the contact between operators and sodium cyanide; The post is well ventilated to reduce the harm of cyanide dust, and the cyanide content in the production site shall not exceed 0.3mg/m? ; Sanitary facilities should be complete and emergency measures should be taken. This post should be equipped with special work clothes, gloves, anti-HCN gas mask and oxygen respirator, eye washer and MF2-8 dry powder fire extinguisher.

7. The main physical properties of sodium cyanide

Common industrial products are white blocky or powdery solids, which belong to cubic crystal system.

Soluble in water, ammonia, ethanol and methanol, slightly soluble in SO2 solution, it belongs to a kind of drama drug, easy to deliquesce, slightly bitter almond flavor, relative density 1.596, melting point 563.7℃, boiling point 1496℃. The vapor pressure is 0.76 mmHg (at 800℃), 1.00 mmHg (8 17℃).

After the formation of HCN, the flash point of HCN is-17.8℃, the spontaneous combustion point is 538℃, and the explosion limit is 5.6-40%, which is highly toxic.

Sodium cyanide is an important basic chemical raw material, which is used in basic chemical synthesis, electroplating, metallurgy and organic synthesis of medicine, pesticide and metal treatment.

8. Stability and reaction characteristics of sodium cyanide

Sodium cyanide is a relatively active compound, which easily reacts with acid, even with weak acid. Metals such as iron, zinc, nickel, copper, cobalt, silver, cadmium, etc. are dissolved in sodium cyanide aqueous solution to generate corresponding cyanide. With the participation of oxygen, precious metals such as gold and silver can be dissolved to form complexes, and aqueous solutions can undergo hydrolysis reactions.

9. Mechanism of cyanide poisoning

Cyanide rapidly dissociates cyano (CN-) after it enters human body. Cyanide ions can quickly combine with oxidized cytochrome oxidase (Fe++) in vivo and prevent it from being reduced to reduced cytochrome oxidase (Fe++) by cytochrome. Therefore, the function of delivering oxygen is lost, resulting in tissue hypoxia and suffocation.

9. 1. Poisoning manifestations

9. 1. 1. Mild poisoning

Headache, dizziness, fatigue, chest tightness, tears, runny nose, nausea, vomiting, dyspnea, bitter almond taste in the mouth, etc.

9. 1.2. Severe poisoning

In addition to the gradual aggravation of mild poisoning symptoms, due to the aggravation of hypoxia, shortness of breath, chest tightness, arrhythmia, irritability, convulsions, disturbance of consciousness, coma, blood pressure drop, shallow breathing, slow down or even stop completely. Oral administration or inhalation of a large amount of high concentration hydrocyanic acid can immediately cause respiratory and cardiac arrest.

10. Environmental protection

In the process of using sodium cyanide, cyanide mainly pollutes the environment.

Cyanide discharged from industrial wastewater is highly toxic to fish. When the concentration of cyanide in water reaches 0.5mg/L, 20% of the fish will die within two hours and all will die within one day. Cyanide can be degraded in the environment. The high NH3-N content in wastewater discharged from cyanide-containing wastewater treatment is likely to cause eutrophication of water resources, which will lead to a large number of phytoplankton reproduction, reduce the transparency of water body, reduce dissolved oxygen, threaten the survival of fish and cause the water quality to stink.

10. 1. Environmental protection standard

10. 1. 1. Water environmental quality standard

According to Class III standard in GB3838-88 Environmental Quality Standard for Surface Water.

The total amount of cyanide in surface water shall not exceed 0.2 mg/L.

10. 1.2. air quality standard

There is no given value in the national standard for cyanide content in the atmosphere, and the average value of cyanide content in foreign standard atmosphere shall not be greater than 0.0 1mg/m3. The Hygienic Standard for the Design of Industrial Enterprises (TJ36-79) stipulates that the maximum allowable concentration of cyanide in the air of production posts is 0.3mg/m3.

10. 1.3. Discharge standard of "three wastes"

The Trial Standard for Industrial "Three Wastes" (GBJ4-73) has a maximum allowable discharge concentration of cyanide in industrial wastewater of 0.5mg/L (calculated by free cyanide), but there is no standard for cyanide in waste gas, so it is required to allow a very small concentration according to the discharge standard of similar substances.

1 1. sodium cyanide packaging and pollutant treatment methods

The packaging of sodium cyanide and the treatment of pollutants must be washed with water first, and the washed aqueous solution must be collected and concentrated. There are many methods to treat wastewater solution, such as alkaline chlorination, electrolytic oxidation, pressure hydrolysis, bio-iron, ferrous sulfate and so on, among which alkaline chlorination is the most commonly used method.

This manual mainly introduces alkali chlorination and pressure hydrolysis.

1 1. 1. Alkaline chlorination

Adjust the pH value of cyanide-containing wastewater to 8.5-9, and add chlorine-containing oxidant to oxidize and decompose cyanide. The chlorine ion oxidizer can be bleaching solution (mainly NaCLO) or chlorine gas (CL2, HCLO when dissolved in water). This method is easy to operate, and the treated wastewater has low cyanide content, but it is only suitable for wastewater with low cyanide content.

1 1.2. Pressure hydrolysis method

Alkali is added into a closed container, and cyanide-containing wastewater is heated and pressurized to hydrolyze cyanide to generate nontoxic sodium formate and ammonia.

The pressure hydrolysis method has wide adaptability to cyanide concentration in wastewater, and can also treat cyanide complexes. Simple operation, but complex process and high cost.

1 1.3. For wastewater with large treatment capacity and high cyanide content, the above two methods can be used at the same time to make the discharged wastewater meet the standard.

For the treatment of a small amount of packaging materials and pollutants, it can be directly soaked in bleaching solution, and then burned and buried after inspection.

For sodium cyanide packaging, it is not allowed to be used for purposes related to the food industry.

12. Packaging and transportation

12. 1. Packaging

"Qingyi" brand sodium cyanide is packed in a sealed iron drum, lined with plastic bags, with an opening at the top and a lid. The specification is φ395×675mm, the net weight of each barrel is 50kg, and the packaging category is 6. 1. The design of the barrel is firm and clear, which conforms to the "highly toxic mark" in figure GB190-90. The barrel is made of carbon steel. The packaging technology meets the requirements of the International Maritime Dangerous Goods Code.

12.2. Matters needing attention in transporting solid and liquid sodium cyanide

When transporting solid sodium cyanide by railway, it is required to send the whole vehicle according to the Railway Dangerous Goods Transport Rules formulated by the Ministry of Railways, with two people on board. Loading and unloading vehicles must use special vehicles marked with the word "WS".

Before and after loading and unloading sodium cyanide, the loaded trucks must be cleaned and ventilated. Do not install the above taboo items with each other.

When transporting solid and liquid sodium cyanide by road, in order to ensure the transportation safety, it is necessary to go through the relevant procedures such as road transportation license and "personal insurance, cargo insurance and vehicle insurance", and handle the annual inspection of driver's license and other transportation expenses on time to keep the car in good condition.

Before loading sodium cyanide, carefully check whether the goods are fastened and whether the valve leaks. During driving, always stop to check whether the goods are loose and wet, and solve the problems in time. Parking accommodation must be in a regular parking lot patrolled 24 hours a day. After unloading the goods, the car should be carefully cleaned in time to prevent sodium cyanide from leaking, polluting, losing, stealing and poisoning.

It is forbidden to carry irrelevant personnel, other goods, stop and put them in disorder, and not to park in densely populated areas and downtown areas. Each vehicle must be equipped with 1-2 escort cover, mask, personal protective equipment and corresponding fire-fighting equipment. Personal protective equipment should be worn during loading and unloading to prevent damage, leakage and being wet by rain.

7, 8, the concept of electroplating

It is a process of plating a thin layer of other metals or alloys on the surface of some metals by using the principle of electrolysis. During electroplating, the plated metal is used as an anode, which is oxidized into cations and enters the electroplating solution; The metal product to be plated is used as a cathode, and the cations of the plated metal are reduced on the metal surface to form a coating. In order to eliminate the interference of other cations and make the coating uniform and firm, it is necessary to use a solution containing metal cations in the coating as electroplating solution to keep the concentration of metal cations in the coating unchanged. The purpose of electroplating is to deposit metal on the substrate and change the surface properties or dimensions of the substrate. Electroplating can enhance the corrosion resistance of metals (corrosion-resistant metals are mostly used as coating metals), increase hardness, prevent wear, and improve conductivity, lubricity, heat resistance and beautiful surface.

[Edit this paragraph] Electroplating

The technology of depositing metal coatings with good adhesion on mechanical products by electrolysis, but with different properties and matrix materials. Electroplated coating is more uniform than hot dip coating, generally thinner, ranging from several microns to dozens of microns. Through electroplating, we can obtain decorative protection and functional surface layer on mechanical products, and also repair worn and machined workpieces. The coating is mostly a single metal or alloy, such as titanium target, zinc, cadmium, gold or brass, bronze and so on. There are also dispersion layers, such as nickel-silicon carbide and nickel-graphite fluoride. There are also cladding layers, such as Cu-Ni-Cr layer on steel and Ag-In layer on steel. In addition to iron-based cast iron, steel and stainless steel, there are also non-ferrous metals such as ABS plastic, polypropylene, polysulfone and phenolic plastic, but the plastic must undergo special activation and sensitization treatment before electroplating.

[Edit this paragraph] Electroplating principle

In electroplating bath containing electroplating solution, the cleaned and specially pretreated workpiece is used as the cathode, the anode is made of electroplated metal, and the two poles are respectively connected with the positive electrode and the negative electrode of DC power supply. The electroplating solution consists of an aqueous solution containing electroplating metal compounds, conductive salts, buffers, pH regulators and additives. After electrification, the metal ions in the electroplating solution move to the cathode under the action of potential difference, forming a coating. The metal of the anode forms metal ions in the electroplating solution to maintain the concentration of the electroplating metal ions. In some cases, such as chromium plating, it is an insoluble anode made of lead and lead-antimony alloy, which only plays the role of transferring electrons and conducting current. The concentration of chromium ions in the electrolyte is maintained by adding chromium compounds to the plating solution regularly. During electroplating, anode material quality, electroplating solution composition, temperature, current density, electrifying time, stirring intensity, precipitated impurities, power waveform, etc. Will affect the quality of the coating and need to be controlled in time.

[Edit this paragraph] Electroplating method

Electroplating can be divided into hanging plating, barrel plating, continuous plating and brush plating, which are mainly related to the size and batch of plated parts. Hanging plating is suitable for general-sized products, such as car bumpers and bicycle handlebars. Roller plating is suitable for small parts, such as fasteners, washers and pins. Continuous electroplating is suitable for large-scale production of wire and strip. Brush plating is suitable for local electroplating or repair. The electroplating solution includes acidic, alkaline, acidic and neutral chromium-containing mixed solutions. No matter what electroplating method is used, electroplating bath, hanger, etc. Contact with the product to be plated and the plating solution should be universal to some extent.

Coating classification

Coatings can be divided into decorative protective coatings and functional coatings.

Decorative protective coatings are mainly chromium coatings on ferrous metals, non-ferrous metals and plastics, especially copper-nickel-chromium coatings on steel and nickel-chromium coatings on zinc and steel. In order to save nickel, people have been able to plate copper-nickel/iron-high sulfur nickel-nickel/iron-low solid nickel-chromium layer on steel. Tin/nickel coatings similar to chromium plating can be used for analytical balances, chemical pumps, valves and flow measuring instruments.

There are many kinds of functional coatings, such as: ① sliding bearing cover coating to improve the compatibility and embeddability with journal, lead-tin, lead-copper-tin, lead-indium and other composite coatings; (2) The hard chromium coating of wear-resistant piston ring of medium and high speed diesel engine can also be used on plastic mold, which has the characteristics of non-sticking to mold and long service life; (3) Copper plating on the sliding surface of large herringbone gear can prevent the sliding surface from early galling; (4) Galvanizing to prevent the steel matrix from atmospheric corrosion; ⑤ Cu-Sn coating prevents nitriding; ⑥ Tin-zinc coating used for brazing and preventing galvanic corrosion between steel and aluminum in the manufacture of radios and televisions. Engineering coatings suitable for repair and manufacture include chromium, silver and copper. , are relatively thick, hard chromium layer can be as thick as 300 microns.

[Edit this paragraph] The electroplating process is basically as follows

1 Connect the electroplated metal to the anode.

2 Connect the parts to be plated to the cathode.

The anode and cathode are connected by an electrolyte solution consisting of positive ions of electroplated metal.

After the DC power supply is connected, the metal of the anode will be oxidized (lose electrons), and the positive ions in the solution will be reduced (gain electrons) at the cathode to form atoms and accumulate on the surface of the cathode.

The aesthetic degree of the electroplated object after electroplating is related to the current. The smaller the current, the more beautiful the electroplated object is. On the contrary, some uneven shapes will appear.

The main uses of electroplating include preventing metal oxidation (such as corrosion) and decoration. Many coins are also electroplated.

Electroplating wastewater (such as ineffective electrolyte) is an important source of water pollution.

9. Physical and chemical properties of toluene diisocyanate;

Main sources of TDI:

First, it mainly comes from interior decoration materials. Polyurethane coatings and adhesives used in interior decoration, in recent years, the amount of domestic polyurethane coatings has increased rapidly, and some families often have white latex coatings yellowing after decoration, mainly because the coatings contain free TDI. In 200 1 year, the General Administration of Quality Supervision, Inspection and Quarantine issued 10 mandatory national standard "Limit of harmful substances in indoor building decoration materials", which strictly limited the free toluene diisocyanate in solvent-based wood coatings and adhesive products commonly used in indoor building decoration, requiring the free TDI content in polyurethane wood coatings to be less than 0.7% and the TDI content in polyurethane adhesive to be 10g/kg.

Secondly, TDI is also the main raw material for making polyurethane foam. Polyurethane foam is an indispensable part of household mattress cushions and composite fabrics, and it is also the main material in sofas. The foam contains TDI, which is harmful to the environment and human body, and also has a potential threat to human health. Daily contact will cause adverse stimulation to human skin and respiratory system. In China, a sudden fire broke out in the workshop of a county-level foam factory, which led to an explosion in the adjacent raw material warehouse, resulting in acute poisoning of TDI gas for 67 firefighters.

Thirdly, TDI also comes from polyurethane elastic floor, which is a new material developed in recent years. Widely used in electronic rooms, hotels, reception rooms and other ground facilities. Especially in indoor and outdoor sports facilities such as stadiums, gymnasiums, plastic runways, pedestrian bridges, etc. Because its main component is polyurethane material, TDI in the material will be released continuously under high temperature or strong light, and you will smell an unpleasant smell when you exercise on the runway in summer. The indoor environmental monitoring center has received complaints and reflections in this regard. In Taiwan Province Province, there was an incident in which students were collectively poisoned by inhaling toxic gas during physical education class on the newly-built plastic stadium floor. The International Sports Runway Technology Association, an expert from the Institute of Basic Education of Beijing Academy of Educational Sciences, has clearly pointed out: "Europe will no longer accept polyurethane sports runways containing TDI."

In addition, TDI also comes from polyurethane leather finishing agent, which is a high and medium-grade leather finishing material gradually developed in recent ten years. Good comprehensive performance, strong adhesion and good wear resistance, which fundamentally solves the common shortcomings of propylene resin, such as hot sticking and cold brittleness. TDI also exists in its main raw materials.

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