Cradle to Consumer
Identity ID
eecfa26f-3ebe-41ba-9fef-5f2cc90bd165
Materials
Associated ID
a24f652f-ef1e-469c-ba6d-a0b4eacf7ec8
Included activities starts
Included activities ends
Description
This dataset is a market dataset representing the consumption market of the region. The dataset includes the transport of the product from the gate to the consumption end, and the transport service is calculated based on the transport situation of the product in the region. The product represented by this dataset is the treatment of lead anode slime (a valuable enrichment by-product of the lead smelting stage), from which silver ingot is prepared through the combined hydrometallurgical and pyrometallurgical purification and refining process of comprehensive recovery of lead anode slime. Silver ingot is a high-purity refined silver product with a silver content of 99.99%, silver-white in colour with a metallic lustre, with excellent physical properties, ductility second only to gold, and can be pressed into thin sheets or drawn into fine wires; it also possesses excellent electrical and thermal conductivity; its melting point is about 961.93℃ and boiling point about 2212℃. At room temperature its chemical properties are relatively stable and it is not easily oxidized, but in sulfur-containing environments it easily forms black silver sulfide, and it can dissolve in concentrated nitric acid and concentrated sulfuric acid to form the corresponding silver salt compounds. The product is silver ingot prepared from the treatment of lead anode slime (a valuable enrichment by-product of the lead smelting stage) through the combined hydrometallurgical and pyrometallurgical purification and refining process of comprehensive recovery of lead anode slime. The dataset includes the main raw and auxiliary materials, energy and waste of the production process; infrastructure such as production equipment manufacturing and plant construction is not included within the dataset boundary; the data inventory is formed by merging data from multiple sources.
Activity Description
The entire production process includes lead anode slime recycling. The process is mainly divided into three parts, namely reduction smelting, oxidation smelting and electrolytic refining. The entire process covers the process from lead anode slime to silver ingots.
Process Description
The product is lead anode slime (a valuable enrichment by-product of the lead smelting process), which is purified and refined through a combined hydrometallurgical and pyrometallurgical process for comprehensive recovery of lead anode slime to produce silver ingots. Silver ingot is a silver-white shiny metal with a silver content of 99.99%. Its ductility is second only to gold. It can be pressed into thin sheets or drawn into filaments. It has excellent electrical and thermal conductivity. Silver is chemically stable at room temperature and is not easily oxidized, but it will produce black silver sulfide in a sulfur-containing environment. It is soluble in concentrated nitric acid and concentrated sulfuric acid to produce compounds such as silver nitrate and silver sulfate. The melting point of silver is about 961.93°C, and the boiling point is about 2212°C. Due to its excellent physical and chemical properties, silver is widely used in currency, decoration, catalysts and chemical industries.
Time period
2021
2026
Geography
China
Geography comment
Generated by merging multiple data sets in this geographical location.
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
The technological process of silver ingot production is mainly divided into three parts, namely reduction smelting, oxidation smelting and electrolytic refining. First of all, the reduction smelting operation is divided into steps such as feeding, melting, slag making, precipitation, slag discharge and noble lead discharge. The prepared charge is added into the furnace in batches or batches. The furnace temperature is preferably 700 to 900°C when adding. The temperature is raised to 1200 to 1300°C during melting. At the same time, air is blown into the melt to stir the charge and promote oxidation and slagging. Secondly, the precious lead produced by the precious lead furnace is poured into buns and transported by a bridge crane to the silver separation furnace for oxidation and refining. After charging, as the furnace temperature rises, Pb in the charge is first oxidized to form PbO, and then due to the transfer effect of PbO on oxygen, arsenic and antimony are oxidized; a small amount of arsenic and antimony enters the slag in the form of arsenic (antimony)ate, and most of the oxidized volatilizes into the furnace gas. After lead, arsenic, and antimony are oxidized to form slag or volatilize, bismuth begins to oxidize to form Bi2O3 and enters the slag, producing early oxidation slag and late oxidation slag (i.e., bismuth oxide slag). After bismuth is removed, soda ash is added to the charge to produce tellurium in the raw material in the form of tellurium-alkali slag. Gold and silver are not oxidized during the oxidation refining process. Except for a very small amount of gold and silver that volatilizes or is mechanically entrained into the slag, the rest is produced in the form of gold and silver alloy plates and sent to the gold and silver workshop for electrolysis and refining. Finally, according to the difference in standard electrode potential of each metal in the gold-silver alloy plate, nitric acid and silver nitrate aqueous solutions are used as electrolytic media. When current is passed through, metals that are more electropositive than silver, such as gold and platinum group elements, do not undergo electrochemical dissolution and remain in the anode mud; metals that are more electronegative than silver, such as Cu, Bi, Pb, As, Sb, etc., dissolve together with the silver and enter the solution. During the electrolysis process, silver dissolves from the anode into the electrolyte, and is discharged at the cathode to precipitate dendritic metallic silver crystals, which are scraped back and forth by the scraper and fall to the bottom of the tank. In order to ensure the quality of electrolytic silver at the bottom of the tank, the coarse silver anode must be placed in a diaphragm bag to prevent anode mud and residual electrodes from falling into the bottom of the tank and contaminating the electrolytic silver powder. The electrolytic silver taken out is placed in a filter tank, washed with hot water until the washing liquid is no longer green or slightly green, then dried and sent to a silver melting furnace for ingot casting. At the same time, gold ingots are produced during the electrolytic refining process.