Low-toxic core sands for mould cores pattern - making in a heated rig

The innovative method of physical and chemical analysis was first used for core sand research that, unlike the method of tests and errors, radically shortens the scope of an experimental work in order to find the optimal core sands compoundings. Some results of the investigations based on the physical and chemical analysis for obtaining the compoundings of low - toxic core sands using hot hardening of a new generation without containing resins are presented. Such compoundings impart more advanced technical, economical and ecological indicators to the process of cores moulding using a heated rig. The development of such mixtures relies on low - toxic technical lignosulphonates (LTTLS) binders containing a modifier. The mixture of vat residues of organic synthesis in water having volume relationship in the proportion of 6:1 was used as a modifier. The search of technological additions set increasing LTTLS binder properties was conducted. To put into practice the declared purpose we investigated the additions of marshalit, boric acid and iron minium influences on the mixtures properties. It was demonstrated that only the joint use of the above - mentioned three technological additions may result in an effective influence of each of them on mixtures properties. An additional introduction of «KO» solution in kerosene turned out to be effective, as well. The given research results lie in presenting mixtures compoundings based on LTTLS having physical and mechanical indicators usually characterizing resins mixtures. Some mixtures containing the additions of a wasted zinc - chromium catalyst having good ecological properties and being applicable to the cores molding of a wide range of pig iron and steel castings were elaborated.