Feasibility study on addition of a colourant to commercially used fire-retardant formulations to enable visual distinguishability between treated and untreated mine support timber

Abstract

ENGLISH SUMMARY: The ability to visually distinguish between fire-retardant treated and untreated mining support timber, treated with ammonium sulphate and ammonium phosphate salts, is very difficult. In fact, once treated and allowed to dry for approximately three days, it visually becomes totally non-distinguishable from untreated timber. The project objective is to identify a suitable colourant which can be incorporated into the fire-retardant formulation which will enable visual distinction between fire-retardant treated and untreated mining timber support on a cost effective basis. The following aspects were evaluated: - Compatability and stability within fire-retardant formulations. - Colour effectiveness and fastness. - Effect on combustion. The results showed that: * Three of the chemical colourants proved to be compatible and stable at two ranges of temperatures. Colourants were Acid Green, Bazazol Red 76L and Malachite Green. * Of the colourants evaluated, Malachite Green and Bazazol Red 76L performed most satisfactorily over two exposure trials, i.e. controlled weather-o-meter and natural exposure. * All three colouration chemicals had no effect on the combustibility of timber when included into the fire-retardant formulations. * The inclusion of a colourant into the fire-retardant can be performed in such a manner that fireretardant treatment economy is hardly affected. * Large scale evaluations need to be performed to verify colour efficiency over time.

AFRIKAANSE OPSOMMING: Dit is uiters moeilik om visueel tussen mynhout wat behandel is met brandvertraag chemikalie, hoofsaaklik ammonium sulfaat en ammonium fosfaat soute, en onbehandelde mynhout te onderskei. Daar is bykans geen visuele onderskeid sodra die behandelde hout toegelaat was om vir drie dae lugdroog te word. Die projek doelwit is om 'n geskikte kleurstofte vind wat tesame met die brand vertraag chemikalie gebruik kan word om sodoende die brand vertraag behandelde hout visueel kan onderskei van onbehandelde mynhout op'n koste-effektiewe basis. Evaluasie wat die ondergenoemde insluit is uitgevoer: - Aanpasbaarheid en stabiliteit wanneer gemeng met brand-vertraag chemikalie. - Kleur effektiewiteit en langdurigheid. - Effek van kleurstof op brandbaarheid. *Die resultate toon dat: Drie van die kleurstowwe wat ondersoek is, aanpasbaar en stabiel voorkom by twee blootstellings temperatuur reekse. Die kleurstowwe is Acid Green, Bazol Red 76L en Malachite Green. *Tydens blootstelling gedurende gekontrolleerde blootstelling, verwering Malachite Green die beste vertoon het. (b) OPSOMMING (vervolgend) *Daar is gevind dat geen van die kleurstowwe 'n invloed op die brandbaarheid getoon het nie. * Die byvoeging van brandvertraagmiddel In dra kleurstof minimaal van brand vertraag behandeling. tesame met die by tot die koste * Groot-skaal se behandeling tesame met die kleurstof behoort uitgevoer te word om kleur effektiewiteit te bevestig.