Abstract: In order to solve the problem of harmless and resource of bulk mineral sludge and red mud,regard dehydrated
slime and red mud as the research objects,combined application of bio-organic fertilizer compound fertilizer and potted corn
planting,the effect of fertilizer-maize synergy on the reconstruction of the soil formation of red mud and mine sludge and heavy
metals properties was explored by analyzing the physical and chemical properties,fertility status and heavy metals of the substrate.
The results showed that bio-organic fertiliser with compound fertiliser significantly promoted the growth of corn,resulting
in a significant increase in corn plant height and root length compared to the control;Substrate for the soilization disposal of red
mud and mine sludge matrix decreased from 1. 1 g/ cm3 to 0. 9 g/ cm3,and the porosity increased from 60% to 65%,physical
structure improved,microscopic spherical morphology,the formation of agglomerates and better connectivity. At 60 d of growth,
the pH and EC values of the substrate for the soilization disposal of red mud and mine sludge decreased to 7. 72 and 476. 9
μS/ cm,all in accordance with relevant standards;Organic matter and alkaline dissolved nitrogen contents were upgraded to the
fifth level in the Nutrient Classification of the Second National Soil Census,while effective phosphorus and quick-acting potassi
um contents were maintained at the third and second levels,compared with the control treatment of the highest were up 0. 13,
0. 08,6. 28 and 2. 51 times;The highest transfer and enrichment coefficients for Cr,As,Pb and Hg heavy metals of corn to the
substrate for the soilization disposal of red mud and mine sludge were 0. 78 and 0. 721,respectively,which were less than 1,indicating
that these heavy metals were not transferred and enriched to corn plants. Pearson correlation analysis showed that pH
significantly affected substrate phosphorus and potassium nutrient effectiveness and passivation of Cr,As,Pb and Hg heavy
metals. The results of this study can provide a reference for the ecological restoration of red mud and mineral mud soil.

Key words: red mud,mine sludge,soilization disposal,fertilizer,corn,mine ecological restoration