Table 1.

Proximate elemental composition (%) of tested Siberian leonardite.

Concentration	Elements
25–40%	C, K
1–2%	H, Ca, Si, Fe
0.1–1%	N, Al, S, Cl, Sr
0.01–0.1%	Na, Mg, Ti, V, Cr, Ni, Zr, Sb, Cs
0.001–0.01%	Zn, Ga, Br, Rb, Y, Nb, Cd, In, Sn, Te, Hf, Hg
<0.001%	P, Mn, Co, Cu, Ge, As, Se, Mo, Ag, I, Ba, La, Ce, Ta, W, Tl, Pb, Bi, Th, U