Contamination from brass

Schock MR, Neff CH. 1988. Trace metal contamination from brass fittings. J Am Waterworks Assoc 80 47-56. 

For CRECEP, values between 5 and 10 ig were observed, but lead was also detected in the blank at the same level. In that case, a small, variable contamination by lead comes from materials before the rigs (a few centimetres of galvanized steel, and brass devices) and carmot be imputed to contamination from brass fittings. 

HazTECH News. September 8, 1988. "A Process for Treating Lead-Contaminated Sand from Brass and Bronze Foundries. " HazTECH News. 

At the sampling step, contamination from sampling bottles and hydrowire should be minimized [10], Old types of sampling devices such as Nansen and Knudsen are constructed mostly from brass, which may cause contamination of Cu and Zn into seawater. The recently developed Niskin plastic sampling bottle provides less contamination from the sampler walls. However, the materials used for the end-caps or springs, rubber or Teflon-coated stainless steel, sometimes release significant amounts of Ba, Cu, Sb and Zn [14]. 

In the preparation of handsheets, the NBS NBH furnish was soaked for 2 h in 0.0005% Ca(OH)2 solution prior to the beating step. The pulp was then beaten in deionized water containing sodium borohydride (0.1% pulp weight) and 0.02% calcium hydroxide or 2.5% calcium carbonate (22). A Craftool Hollander laboratory beater was employed. Handsheets were prepared with a Noble and Wood brass sheet-making machine, which had been painted to prevent the contact of pulp with brass. The metal wire was overlaid with polyester fiber screening (75 mesh). Handsheets were also prepared from the same pulp furnish with the Noble and Wood brass sheet-forming machine before it had been painted. These papers had a copper content of 150 ppm as a result of contamination from the brass. 

Analysis of Ca, Mg, Fe, Mn and Sr in calcite, ankerite and siderite was performed on a JEOL 733 electron microprobe. Accelerating voltage was 15 kV sample current was 12 nA, stabilized on brass. Spot size was 10 pm. Counting time for all elements was 20 s, except for Sr, which was analysed for 60s. Detection limits are approximately 340 ppm for Mg, 450 ppm for Fe, 310 ppm for Mn and 185 ppm for Sr. Totals between 97 and 103% were accepted. Standards were carbonate minerals (calcite for Ca dolomite for Ca, Mg siderite for Fe, Mn and coral for Sr) in the standard collection at the University of Texas electron microprobe laboratory. Beam placement was guided by back-scattered electron imaging. Si was routinely counted by WDS to check for possible contamination from... 

The collective results for contamination 1 copper from brass produced two overlapping statistically distinct groups with no obvious candidate for the rogue result. However, all results were very low and would have little practical significance. 

Raising the pH of the test solution to its equilibrium value with the atmosphere (Test 3) brought the zinc-from-brass results for the three laboratories concerned into the same statistical population. This was an improvement over any of the previous tests, but the effect was not uniform. Thus, only for CRECEP did raising the pH consistently reduce the zinc contamination level as compared with the previous tests on brass. For LHRSP, the zinc levels were actually increased whereas for WRC the result from test 3 was between those of tests 1 and 2 (see Table 4.4d). 

Table 4.6 Ranking severity of contamination of metals from brass coupons exposed to the local laboratory waters being supplied to the respective pipe rigs...

The order of severity of contamination by Zn, Pb and Cu from brass with the different laboratory test waters were approximately the same, for example, the water that is worst for Pb was also worst for Cu and second worst for Zn (Table 4.6). 

This is the removal of oil, grease or other contaminants from the surface of metals, and increasingly plastic components and assemblies. Substrates cleaned include mild steel, brass, copper, polypropylene and printed circuit boards, the level of cleanliness required depending on the application. 

It is important to note that large numbers of water systems in the U.S., having no lead service lines or interior lead piping, required some form of enhanced corrosion control as a result of the Lead and Copper Rule, due to a combination (not differentiable from the monitoring data) of leaded brasses and soldered joints in copper plumbing. Therefore, the significant lead release observed in the AWWARF study represented lead contamination from waters already adjusted for some corrosion control, and would not represent nearly a worst-case scenario as may be present elsewhere in North America or Europe. 

There is no doubt that the contamination of the atmosphere with trace elements which commonly occurs in industrial areas can have pronounced effects on biological systems, and Ruehling and Tyler [164] have discussed the depressant effect on the decomposition of spruce needle litter at a number of sites around two metal-processing industrial plants in central and south-eastern Sweden, emitting cadmium, copper, nickel and zinc, and cadmium, lead and nickel, respectively. Tyler has also reported inhibition of respiration rate and of phosphatase and urease activity in spruce mor, contaminated from a brass foundry in Sweden [165]. 

It is assumed that the only sources of lead in drinking water are lead service lines and any internal lead pipes within premises and that lead contamination is due solely to the process of dissolution. The model does not simulate lead releases from brass or galvanic corrosion, nor particulate lead releases however, correction factors can be apphed if necessary. 

Drinking water can be contaminated with lead from brass or chrome-plated brass faucets. Most of these faucets that were purchased before 1997 contain up to 8 % lead (Massachusetts Water Resources Authority 2012). Federal legislation enacted in 2010 mandates that all faucets purchased after January 14,2014 have no more than a weighted average of 0.25 % lead per wetted surface area. 

Latex compound viscosity obviously forms an important aspect of dipped product manufacture. Accurate measurement by a Brookfield or similar viscometer is desirable to estabhsh the fundamental viscosity of a compound, but Flow-Cup viscometers (Ford B.3 Cup) are more commonly used for day-to-day control of latex compounds during compounding and product manufacture. It is necessary to ensure that only stainless steel flow cups are used, if the measured latex is allowed to return to the production tanks brass cups yield an unacceptable level of copper contamination, which adversely affects aging properties of products made from copper-contaminated mbber compound. 

Chlorosulfuric acid attacks brass, bronze, lead, and most other nonferrous metals. From a corrosion standpoint, carbon steel and cast Hon are acceptable below 35°C provided color and Hon content is not a concern. Stainless steels (300-series) and certain aluminum alloys are acceptable materials of constmction, as is HasteUoy. Glass, glass-lined steel, or Teflon-lined piping and equipment are the preferred materials at elevated temperatures and/or high velocities or where trace Hon contamination is a problem, such as in the synthetic detergent industry. 

The presence of trace quantities of mercury in a process stream can cause the catastrophic failure of brass heat-exchanger tubes, from the formation of a mercury-copper amalgam. Incidents have occurred where the contamination has come from unsuspected sources, such as the failure of mercury-in-steel thermometers. 

The process flow sheet was first tested for direct leaching of steel mill flue dust and production of zinc metal by electrowinning. The tests were performed in a continuously operating pilot plant, producing 10-20 kg/day zinc metal. The same pilot plant was then used for treating copper/zinc-rich brass mill flue dust in a closed loop operation, recycling all the zinc solvent extraction raffinate to the copper circuit leach section. In the zinc circuit leach section, only the amount of zinc rich dust necessary for neutralization of the copper solvent extraction raffinate was used. The results obtained from the pilot plant tests indicated contamination problems within the solvent extraction loops. The estimation of economic data showed a weak return on the assets compared with the alkali route, and sensitivity toward the raw material price. 

In most foundries, casting sands are recycled internally until they can no longer be used for casting. At that time, many of the sands, such as those from iron foundries, are landfilled as nonhazardous waste. Casting sands used in the production of brass castings may be contaminated with lead and must be disposed of as hazardous waste. Methods which can be employed to reduce the toxicity or volume of these wastes are discussed below ... 

Sands used in the production of brass and bronze castings often pick up lead contamination and must be disposed of as hazardous waste. It has been reported (HazTECH News 1988) that Pittsburgh Mineral and Environmental Technology, Inc. has developed a process that can recover more than 90 percent of the metal value from the sand and render the sand nonhazardous. 

It should not be assumed that the composition of commercial alloys will necessarily correspond to the percentages indicated or that other metals may not be present in small amounts. For example, the properties of brass differ with variation in the copper-zinc ratio. Similarly, the properties of commercial brass are often profoundly changed by the presence of small quantities of other metals. Since alloys are usually fabricated from metals that have not been subjected to elaborate purification processes, the resulting alloys are frequently contaminated with metals present in the primary ores. 

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