Mercury handling

Eliminate mercury handling No hydrogen in chlorine More adaptable to small installations Smaller brine area system Very pure brine required Some evaporation required to produce 50% caustic... 

Mercury salts are highly toxic and must be handled carefliUy. It is necessary to consult the material safety data sheet prior to handling. Strict adherence to OSHA/EPA regulations is essential. The ACGIH adopted (1991—1992) TLV for mercury as inorganic compounds is TWA 0.1 mg/m and for fluorides as F 2.5 mg/m. ... 

Mercury thermometers are subject to separation of the mercury column or to inclusion of bubbles of the fiU gas. These may result from shipping and handling and cause a scale offset which can usually be seen upon visual examination, and they are always recogni2ed by a 0°C verification check. Manufacturers will suggest means by which these temporary defects may be cured. 

Reactivity. Bromine is nonflammable but may ignite combustibles, such as dry grass, on contact. Handling bromine in a wet atmosphere, extreme heat, and temperatures low enough to cause bromine to soHdify (—6° C) should be avoided. Bromine should be stored in a cool, dry area away from heat. Materials that should not be permitted to contact bromine include combustibles, Hquid ammonia, aluminum, titanium, mercury, sodium, potassium, and magnesium. Bromine attacks some forms of plastics, mbber, and coatings (62). 

Avoid wearing rings. Wear gloves. Wash the hands and gloves after handling mercury Use catchpots under apparatus containing mercury... 

Fluorides and dust are emitted to the air from the fertilizer plant. All aspects of phosphate rock processing and finished product handling generate dust, from grinders and pulverizers, pneumatic conveyors, and screens. The mixer/reactors and dens produce fumes that contain silicon tetrafluoride and hydrogen fluoride. A sulfuric acid plant has two principal air emissions sulfur dioxide and acid mist. If pyrite ore is roasted, there will also be particulates in air emissions that may contain heavy metals such as cadmium, mercury, and lead. 

The principal constituents of the paniculate matter are lead/zinc and iron oxides, but oxides of metals such as arsenic, antimony, cadmium, copper, and mercury are also present, along with metallic sulfates. Dust from raw materials handling contains metals, mainly in sulfidic form, although chlorides, fluorides, and metals in other chemical forms may be present. Off-gases contain fine dust panicles and volatile impurities such as arsenic, fluorine, and mercury. 

When used as a vacuum pump, these single-stage units can pull vacuum down to 27 in. of mercury vacuum (not absolute) and handle approximately 1,800 ft /min. As two-stage vacuum pumps they can pull vacuum to 29.97 in. mercury (see Chapter 6, V. 1 of this series) with about 2,000 cfm at high vacuum. 

One form of calomel electrode is shown in Fig. 15.1(a). It consists of a stoppered glass vessel provided with a bent side tube fitted with a three-way tap which carries a short upper and a long lower tube the latter is drawn out to a constriction at the bottom end. A short platinum wire is fused into the bottom of the vessel so that it protrudes into the interior, and a narrow glass tube sealed to the bottom of the vessel is bent round parallel to the vessel. A little mercury placed in the bottom of this tube provides electrical connection with the interior of the vessel through the sealed-in platinum wire. Mercury and mercury compounds must be handled with care (see Section 16.8). 

The first is the story of the high school physics teacher who came down with a strange illness eventually diagnosed as mercury poisoning. The cause Over the years, minute amounts of this metal had been spilled in the poorly ventilated lecture room. The students suffered no ill effects since they spent so little time there. Fortunately, the teacher recovered, the room was completely refurbished, and strict rules were introduced concerning the handling of mercury. 

When questioned about the safety of such procedures, the chief chemist had a quick answer We have done it this way for over 20 years and never had a problem. Such handling of mercury would be unthinkable today. 

Mass effects due to some ions in salts. It is generally observed that there is a greater instability amongst compounds containing heavy atoms compared with elements in the first periods of the periodic tabie.This can be observed by analysing enthalpies of formation of ammonia, phosphine, arsine and stibine (see previous table for the last three). In the same way, it is easier to handle sodium azide than lead azide, which is a primary explosive for detonators. It is exactly the same with the relatively highly stable zinc and cadmium thiocyanates and the much less stable mercury thiocyanate. 

Use caution when handling the mercury lamp. Mercury is toxic. 

For equipment handling acetylene the pure metals, or alloys containing copper, silver, mercury, gold, must be avoided to prevent the formation of explosive acetylides. 

Handling and processing of stripped components containing particularly hazardous substances Batteries and accumulators are classified as hazardous wastes even if they are recycled. Mercury is classified as a hazardous waste and can be recovered in special plants. Condensers containing PCBs must be incinerated in a hazardous waste incineration plant. 

How can the Ecodesign Directive be further developed to handle the RISKCYCLE-topic So far, pollution issues are involved in the context of product evaluation and the derivation of product standards, but rather in the sense of LCA to capture the energy side and the other relevant environmental indicators. The topic of mercury in compact fluorescent lamps (CFL) has made it clear that pollution issues can be quite important in the context of this Directive. However, relevant limits for energy saving lamps were first set by a waste-related regulation, namely the Annex of the WEEE Directive [7]. 

Electronic products become e-waste when they are deemed at the end of their useful life. Nonfunctioning or obsolescent TVs, computers, printers, photocopiers, cell phones, fax machines, home appliances, lighting equipment, games and such, when no longer wanted, come to constitute e-waste. These electronic products contain many materials requiring special end-of-life handling, most prominently lead, mercury, arsenic, chromium, cadmium, and plastics capable of releasing dioxins and furans. 

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