© by PSP Volume 21 – No 5a. 2012 Fresenius Environmental Bulletin 1334 A NEW FILL MATERIAL TECHNOLOGY FOR EX-MINING LAND RECLAMATION AND CONSTRUCTION PURPOSES Muhammad Aqeel Ashraf 1, *, Mohd. Jamil Maah 1 and Ismail Yusoff 2 1 Department of Chemistry, University of Malaya, Kuala Lumpur 50603, Malaysia 2 Department of Geology, University of Malaya, Kuala Lumpur 50603, Malaysia ABSTRACT Rapid industrial and commercial expansion in recent years has created the need for more land. One of the op- tions to create more land is to reclaim ex-mining land. Ex- mining land contains numerous mined out lakes and ponds. Numerous methods are available to fill these lakes and ponds. The ex-mining land consists of a variety of materi- als, such as sand, clay, slime and organic peat. A new land- fill method, which is economically competitive, technologi- cally feasible and will not contribute to any environmental problems, was developed. It is based on flocculation of slurry slime with Natural Organic Polymer (NOP) or Poly Vinyl Acetate (PVC), mixed with residual soil and usage of the flocculated slurry slime as part of the fill material. The physical and geotechnical properties of the floccu- lated slurry were assessed by laboratory tests, including pH and Eh measurements, acid neutralization capacity de- termination, hydraulic conductivity and comparison and cost analysis with conventional fill materials, such as sands. The flocculated slurry slime was slightly alkaline, with pH 8.4, Eh value of 171 mV, negligible ANC, and hy- draulic conductivity of 8x10 –5 - 7x10 –4 m/s. It was also found that the material is unlikely to cause significant change in redox conditions of the subsurface environment over a long-term period. The proposed method is more feasible as compared to other methods in comparison and cost analysis. In general, the flocculated slurry slime is suit- able to be used as a fill material for land reclamation. KEYWORDS: mining waste land, construction, fill material, clas- sical methods, flocculated slurry slime 1. INTRODUCTION During recent years, mine land reclamation and eco- logical rehabilitation has become the subject of common concern by countries in the world, and this trend is in- creasingly widespread. Land-use is a decision to be made * Corresponding author by the society. Land-use can be changed – society can decide to change the land-use on a rehabilitated colliery from crops to housing or industrial estates, but mines have an obligation to ensure that no net loss in land capability occurs [1]. This must be the primary objective in rehabili- tating mined land. Where land capability is not preserved, society is deprived of choice. Degraded lands can poten- tially support fewer land-use possibilities – no crops, for instance. Some argue that agreements with communities regarding land-use can be made prior to rehabilitation whereby a lower quality of rehabilitation is acceptable [2, 3]. This may occur, for example, if the pre-mining land capability is arable, but the community is satisfied with grazing as post-mining land capability. Such decisions, even when based on community preferences, do not pro- mote sustainability. Soil formation takes thousands of years and, by only restoring a fraction of the original land capa- bility, future generations are deprived of the choices that are available to this generation [4, 5]. Malaysia is an important country in mining production, and the exploitation of mineral resources plays a decisive role in national economy development. Currently, the min- ing industry is responsible for producing a sizeable pro- portion of the nation’s merchandise export income, and its relative importance is continuously increasing. Recent available data (2000) showed that the mining industry consisted of 87 mines extracting ores of gold, tin, nickel, copper, aluminium, manganese, iron and chromium [6, 7]. In addition, there are more than 18 establishments produc- ing non-metallic minerals and construction materials. The number of mining operations is rapidly increasing as explo- rations continue to take place, particularly in the Perak, Penang and Selangor states. How to exploit mineral re- sources rationally but reduce all sorts of adverse effects on the human environment in its process, is a major event in people's livelihood [8]. Due to blooming development and rate of urbaniza- tion in Peninsular Malaysia in recent years has created the need of more land, especially land near to the developed areas. Many urban areas have expanded to mined-out land which has numerous mined-out ponds. It has been esti- mated that urban population will double itself every 10 to 15 years and mined-out lakes and ponds in the way of