The effect of nanodispersed iron oxide additives on the formation of the density of carbon refractories

It was established that the addition of nanodispersed iron oxide pigment in an amount of 0,25‒0,50 % provides directional regulation of the chemisorption interaction of the binder and fller during mixing, contributing to an increase in the density of carbon refractories. It is shown that when introducing nano-additives into the carbon composition, it is necessary to adjust the mass of the binder in the direction of reducing its content. The principle of selecting the optimal binder content as a result of the plasticizing effect of nanodispersed iron oxide pigment at the maximum torque on the mixer shaft corresponds to a high level of expended mechanical energy and, accordingly, to intensify the mixing process and provides an increase in the sintering mass during fring.Ill.5. Ref. 14.

The Use of Waste Maroon Marble Powder and Iron Oxide Pigment in the Production of Coloured Self-Compacting Concrete

This work covers some workability, mechanical, and durability properties of coloured self-compacting concrete (SCC) containing maroon marble powder and iron oxide pigment. Pigments with varying amounts were used to produce coloured SCC. For this purpose, ten different series were prepared of which two of the series were pigment free that one of them was the colour of white SCC including limestone powder and the other one was the colour of maroon SCC including maroon marble powder. The other series were containing pigments with varying amounts. The water to binder ratio remained constant for all the series at 0.42. Slump flow, T50 time, V-funnel, and L-box tests were used to determine the workability of coloured SCC. The hardened properties that were determined included density, water absorption, ultrasonic pulse velocity (UPV), compressive strength, abrasion resistance, and impermeability. As workability, experimental results showed that coloured SCC could be obtained by using maroon marble powder and when iron oxide pigment used in amounts less than 6%. The addition of pigment notably increased the water absorption of SCC series. The use of smaller quantities of pigment caused slight increase in compressive strength. Higher pigment content also provided decreases in abrasive resistance, and after exposure to abrasion, mass losses were within the range of 0.89%–2.12% and the abrasion depths were within the range of 0.9 mm–2.1 mm. Among the varying amounts of pigmented series, M1 series which contains 1% pigment showed the best performance, and the findings indicated that it is possible to successfully utilize maroon marble powder and lower amounts of pigments in producing coloured SCC.