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Measuring and Reporting the Results of Waste Prevention
Published in Norman J. Crampton, Preventing Waste at the Source, 2018
Estimated waste reduction. Dross is the waste byproduct of aluminum melting operations. AAP’s new remelting process reduces dross—from 8% dross under the old process to 2% dross under the new in-plant recycling process. This can be expressed as 0.40 pounds of waste dross reduction per wheel.
Printed Wiring Board Design and Fabrication
Published in Michael Pecht, Handbook of Electronic Package Design, 2018
Denise Burkus Harris, Pradeep Lall
Another approach is to remove the dross as it accumulates during the soldering process, by skimming the surface. The components are soldered or pretinned by dipping them in the solder pot and holding them in the molten solder until the surface is wetted and coated with solder. In the case of leadless ceramic chip carriers, the carriers are placed on top of the solder and allowed to float on the molten solder. As they float, the molten solder wicks up the castellations, pretinning the I/O of the chip carrier. For producing solder joints in larger applications, the pot is equipped with a pump to generate a wave of solder on the underside of the circuit (Figure 3.19). The solder wave is adjusted to impinge on the underside of the circuit board. This wave simultaneously supplies solder to all the solder joints on the board.
Metals II: Details About Specific Metals
Published in Ronald Scott, of Industrial Hygiene, 2018
Metals such as copper, zinc, magnesium, chromium, beryllium, nickel, silicon, and titanium are added to the melt to produce desired alloys. The molten aluminum is then cast directly into products or into ingots which later are formed into products by rolling, forging, or extruding. The dross and oxide residue at the bottom of the furnace are rich enough sources of aluminum to justify reprocessing in primary aluminum recovery systems. Dross is often wet down when it has been removed. It contains an unpredictable mixture of substances, especially if scrap was added to the melt, and must be treated carefully. Water reacts with nitrides to produce ammonia. Many of the metal salts in dross are water soluble, so runoff must be prevented from soaking into the ground such that groundwater could be contaminated.
Recovery of Al2O3/Al powder from aluminum dross to utilize as reinforcement along with graphene in the synthesis of aluminum-based composite
Published in Particulate Science and Technology, 2023
Shashi Prakash Dwivedi, Shubham Sharma
Aluminum dross is the combination of nonmetallic materials (oxide and salt) and elemental metal is formed while molten aluminum gets in touch with air on its outer surface. Dross is divided into two categories in terms of metal content. The dross with high metal content (total weight of dross is more than 50 wt. %) is named as primary dross (Also known as rich dross, wet dross, and white dross), which typically has a dense or cluster form (Zawrah et al. 2022). Primary dross is generally formed during primary aluminum fabrication. It is faintly hazardous and utilized in secondary Al production or the steel industry. The dross with low metal content (total weight of dross is between 5 and 20 wt. %) is known as secondary dross (other common names: lean dross, dry dross, or black dross), which generally has a granular shape. The secondary or granular dross has higher gas evolution and salt content than the primary or compact dross. However, there is the problem of dust has been observed during the Al secondary production from the cyclones and the filters (Taha, Zawrah, and Abomostafa 2022). The European Waste Catalogue (EWC) has classified these powders as hazardous waste (code number: 100321). Recycling of dross waste in other areas especially in the development of composite is an emerging area of research, due to these facts, aluminum dross is utilized as reinforcement in the development of aluminum-based composite in the present study.
Influence of secondary aluminum dross (SAD) on compressive strength and water absorption capacity properties of sandcrete block
Published in Cogent Engineering, 2019
David O. Nduka, Opeyemi Joshua, Adekunle M. Ajao, Babatunde F. Ogunbayo, Kunle E. Ogundipe
AD is one of the residual by-products that is generated from aluminum refining and smelting processes. The major constituents of AD are aluminum, aluminum oxides, and different salts in varying compositions (Murajama et al., 2012). Primary dross with associated names (white dross, wet dross and rich dross) and secondary dross (black dross, dry dross and lean dross) are two types of dross produced from either primary or secondary refining of aluminum (Mahinroosta & Allahverdi, 2018a; Liu, Leong, Hu, & Yang, 2017). Primary dross is stuffed in metal content with about 80% by weight of the total dross obtained from aluminum ingots as raw material (Meshram & Singh, 2018). On the other hand, secondary dross has low metal content of about 5–20% of the weight of the dross obtained from scraps smelting. Additionally, black dross has higher salt content, gas evolution than white dross and granular in shape. Galindo et al. (2015) and Liu et al. (2017) detailed SAD to be hazardous waste that is very combustible, nuisance, poisonous and seepable in accordance with European Catalogue for hazardous waste. Liu et al. (2017) suggest that AD should be treated before landfilling. The treatment according to the authors involves aqueous dissolution at 60°C for 48 h to reduce its reactivity. This combined hydrolysis and heat treatment can convert dross to inert material. Further stabilization can be accomplished with gypsum. It is of researchers’ view that the quantity of dross generated is a function of the type and quality of raw material, operating condition, type of technology and furnace used.
Thermodynamic analysis of waste heat recovery of aluminum dross in electrolytic aluminum industry
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Fan Yang, Qingbo Yu, Zongliang Zuo, Limin Hou
According to statistics, the annual output of hot aluminum dross in our country is 1,600 kt. Because the aluminum dross contains more aluminum, alumina, and other valuable components, most researchers are concerned about the resource reutilization of aluminum dross. Ways of resource reutilization mainly include the recovery of metallic aluminum (Hiraki and Nagasaka 2015; Mah, Toguri, and Smith 1986; Soto and Toguri 1986; Tzonev and Lucheva 2007; Ünlü and Drouet 2002), synthesis of SiAlON ceramics (Izhevskiy et al. 2000), manufacture of polyaluminum chloride and polypropylene composite material (Samat et al. 2017), and hydrogen production (Biganzoli et al. 2013; Hiraki and Akiyama 2009; Hiraki et al. 2005, 2007).