Holtzer Mariusz, Dańko Rafał, Kmita Angelika, Drożyński Dariusz, Kubecki Michał, Skrzyński Mateusz, Roczniak Agnieszka
Faculty of Foundry Engineering, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow, Poland.
Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow, Poland.
Materials (Basel). 2020 Oct 1;13(19):4395. doi: 10.3390/ma13194395.
Increasingly strict regulations, as well as an increased public awareness, are forcing industry, including the foundry industry, to develop new binders for molding sands, which, while being more environmentally friendly, would simultaneously ensure a high quality of castings. Until recently, binders based on synthetic resins were considered to be such binders. However, more accurate investigations indicated that such molding sands subjected to high temperatures of liquid metal generated several harmful, even dangerous substances (carcinogenic and/or mutagenic) from the benzene, toluene, ethylbenzene and xylenes (BTEX) and polycyclic aromatic hydrocarbons groups (PAHs). An assessment of the most widely used molding sands technologies at present with organic binders (synthetic resins) from the no-bake group (furan no-bake and phenolic-ester no-bake) and their harmfulness to the environment and work conditions is presented in this paper. In the first stage of this research, gases (from the BTEX and PAHs groups) emitted when the tested molds were poured with liquid cast iron at 1350 °C were measured (according to the authors' own method). The second stage consisted of measuring the emission of gases released by binders subjected to pyrolysis (the so-called flash pyrolysis), which simulated the effects occurring on the boundary: liquid metal/molding sand. The gases emitted from the tested binders indicated that, in both cases, the emission of harmful and dangerous substances (e.g., benzene) occurs, but, of the given binder systems, this emission was lower for the phenolic-ester no-bake binder. The obtained emission factors of BTEX substances show higher values for furan resin compared to formaldehyde resin; for example, the concentration of benzene per 1 kg of binder for furan no-bake (FNB) was 40,158 mg, while, for phenol-formaldehyde no-bake (PFNB), it was much lower, 30,911 mg. Thus, this system was more environmentally friendly.
日益严格的法规以及公众意识的提高，正迫使包括铸造行业在内的各行业开发新型型砂粘结剂，这些粘结剂在更环保的同时，还能确保铸件的高质量。直到最近，基于合成树脂的粘结剂都被认为是这类粘结剂。然而，更精确的研究表明，这种型砂在液态金属的高温作用下会产生几种来自苯、甲苯、乙苯和二甲苯（BTEX）以及多环芳烃组（PAHs）的有害甚至危险物质（致癌和/或致突变）。本文对目前最广泛使用的采用有机粘结剂（合成树脂）的型砂技术进行了评估，这些粘结剂来自自硬组（呋喃自硬和酚醛酯自硬），并评估了它们对环境和工作条件的危害。在这项研究的第一阶段，测量了在1350℃下用液态铸铁浇注测试模具时所排放的气体（来自BTEX和PAHs组）（根据作者自己的方法）。第二阶段包括测量粘结剂在热解（所谓的快速热解）过程中释放的气体排放，这模拟了在液态金属/型砂界面发生的效应。测试粘结剂排放的气体表明，在这两种情况下，都会产生有害和危险物质（如苯）的排放，但在给定的粘结剂体系中，酚醛酯自硬粘结剂的这种排放较低。所获得的BTEX物质排放因子表明，呋喃树脂的排放因子值高于甲醛树脂；例如，每1千克呋喃自硬（FNB）粘结剂中苯的浓度为40158毫克，而酚醛自硬（PFNB）粘结剂的苯浓度则低得多，为30911毫克。因此，该体系更环保。
