A novel three-dimensional graphene/polyaniline (3DGP) composite was achieved by a hydrothermal method from in situ polymerization of a polyaniline/graphene oxide composite and GO suspension. This 3DGP composite possesses a 3D porous network structure and large specific capacity of 648 F g⁻¹ at a current density of 0.5 A g⁻¹. In particular, the capability can reach 356 F g⁻¹ even at 20.0 A g⁻¹, 537 F g⁻¹ at 1.0 A g⁻¹ can also be achieved after 1000 cycles. Therefore, the 3DGP composite is a suitable and promising electrode material for supercapacitors.

Graphene nanosheets (GSs) were prepared from graphite oxide by thermal exfoliation method. The effect of thermal exfoliation temperature on the structure and supercapacitive performance of GSs has been investigated. The results show that the GSs with pore sizes center around 4.0 nm. With an increase of thermal reduction temperature, the number of stacking layers and the structure disorder degree increase, while the oxygen-containing groups content, BET surface area, and electrical resistivity of GSs decrease. The results indicate that 673 K is the preferable thermal exfoliation temperature to acquire good supercapacitive performance. In this case, the GSs have the best supercapacitive performance (233.1 F g⁻¹) in a 6 mol L⁻¹ KOH electrolyte. The prepared GSs at the preferable thermal exfoliation temperature have good rate performance and cycle stability.

In this research, ammonium chloride was used to calcine Ti-extraction blast furnace slag (EBFS) with the aim of removing iron from it. The influences of calcination temperature, ammonium chloride to EBFS mass ratio and particle size on the rates of iron removal were investigated. The results show that the rate of iron removal increased to almost 100% with increases in calcination temperature and the NH4Cl to EBFS mass ratio, but decreased with increases in particle size. Iron is removed in the form of ferric chloride gas, and ammonium chloride can be recycled by recrystallization after decomposition. The bagdasarrym model was used to describe the calcination process at temperatures below 261°C, which was controlled by nonisothermal crystallization. The reaction kinetic equation was obtained and the apparent activation energy of 67.21 kJ/mol. Ferric chloride reaction product existed in the calcined slag in an amorphous solid state. The shrinking core model was used to describe the calcination process at temperatures above 261°C, which was controlled by surface chemical reactions. The reaction kinetic equation was obtained and the apparent activation energy was found to be 42.05 kJ/mol.