Room and pillar mining involves leaving insitu pillars for local and global support. As the ore-body depletes, with the aim of increasing the life of mine and profitability of operation, there is need to perform pillar recovery operation which can be either partial or full if justified from both safety and economic point of views. Romarmar a lead-zinc room and pillar mine located 15 km from city of Isfahan in Iran operates at small to medium scale with a daily production capacity of 575 tonnes, requires to perform partial pillar recovery to maximise profitability of the mining operation . The current extraction ratio for Romarmar mine is 0.64 which is too low from an economical point of view. Romarmar mine consists of 3 rock masses This thesis focuses on selection of suitable pillar recovery method for Romarmar mine. The author It was observed that pillar stress increases with increasing extraction ratio. Reducing pillar width reduces the pillar confinement which is defined by pillar width to height ratio (W/H) thus pillar strength decreases with increasing extraction ratio. SVC and multinomial logistic models were used for pillar stability analysis. Vertical displacement associated with roof and floor deformation and pillar burst potential were used to establish stability condition of the residual pillars. As the pillar become more slender due to recovery operation, the deformation behaviour becomes more brittle (strain softening behaviour) thus the pillar becomes more prone to pillar burst occurrence. Competent rock mass To justify economic benefits of innovative methods, a cost benefit analysis was performed. Selection of suitable pillar recovery methods from a panel of simulated options for each rock mass ltr"
