Binding Waste Anthracite Fines with Si-Containing Materials as an Alternative Fuel for Foundry Cupola Furnaces

Abstract

An alternative fuel to replace foundry coke in cupolas was developed from waste anthracite fines. Waste anthracite fines were briquetted with Si-containing materials and treated in carbothermal (combination of heat and carbon) conditions that simulated the cupola preheat zone to form silicon carbide nanowires (SCNWs). SCNWs can provide hot crushing strengths, which are important in cupola operations. Lab-scale experiments confirmed that the redox level of the Si-source significantly affected the formation of SiC. With zerovalent silicon, SCNWs were formed within the anthracite pellets. Although amorphous Si (+4) plus anthracite formed SiC, these conditions did not transform the SiC into nanowires. Moreover, under the test conditions, SiC was not formed between crystallized Si (+4) and anthracite. In a full-scale demonstration, bricks made from anthracite fines and zerovalent silicon successfully replaced a part of the foundry coke in a full-scale cupola. In addition to saving in fuel cost, replacing coke by waste anthracite fines can reduce energy consumption and CO2 and other pollution associated with conventional coking.

Experimental investigation on NOx emission characteristics of a new solid fuel made from sewage sludge mixed with coal in combustion

“…and has the ability to precipitate gelatin (Chang and Juang, 2004). The zerovalent silicon and anthracite fines successfully replaced a part of foundry coke, which can reduce energy consumption, CO 2 and other pollution (Huang et al, 2011). The zerovalent silicon and anthracite fines successfully replaced a part of foundry coke, which can reduce energy consumption, CO 2 and other pollution (Huang et al, 2011).…”

Anthracite briquettes with plant byproducts as an ecofriendly fuel for foundries

“…A cupola furnace is used to melt iron and it consists of three distinct regions such as dropping, heating, and melting zone [1]. In order for a carbon source to be used as a fuel in a cupola furnace, it is necessary to keep its porous structure for fast burning as it passes through the three different zones.…”

“…Thus the use of coke leads to environmental pollution through harmful emissions as well as energy loss. Besides the above draw backs, coke is no longer costeffective as the cost of coke increased to 400% in a short span of time, i.e., from 2002 to 2010 [1].…”

“…In order to overcome the above disadvantages we have been developing ecofriendly anthracite briquettes as an alternative fuel to replace the coke because anthracite has similar chemical properties to that of coke [1,3,5]. In our previous studies waste anthracite fines were briquetted into bricks using denatured collagen with silicon metal powder and lignin.…”

“…In our previous studies waste anthracite fines were briquetted into bricks using denatured collagen with silicon metal powder and lignin. This type of briquettes could hold their structure when they were pyrolyzed at 1400 o C for 2 h in a tubular furnace [1] and could be stored for a long time at ambient temperature without loss of structural strength via surface application of clarified neem oil and copper which prevents biological activity on bindered anthracite bricks before use for their optimal performance in cupola furnaces [6]. The 4 structural integrity of these bricks was demonstrated effectively in a full-scale cupola furnace suggesting that the replacement of the conventional coke as a fuel might be feasible [7].…”