Currently, the demand for stone construction materials in Lao PDR to serve industrial and traffic works is very large. Currently, the management of mining activities at limestone quarries in Lao PDR is facing many difficulties due to the existence of many types of mines, mining technologies, and equipment. The occupational safety and environmental protection used at the limestone quarries have not been paid due attention. The loss and waste of natural resources are increasing. In particular, labor accidents caused by unsafe drilling and blasting activities often occur at the limestone quarries of construction materials in all provinces of this country. The article analysed the current situation of drilling and blasting activities at the limestone quarries of construction materials of Lao PDR, thereby proposed a method to assess risks and unsafety in drilling and blasting activities at the limestone quarries for mining the construction materials to improve the efficiency of the mining management and safety in Lao PDR.

In open pit mining, besides the value of the minerals obtained, the cost of waste rock removal determines the efficiency of the mining operation. The paper introduces the rock mass data processing method and modelisation of fractured rock mass to serve the optimal calculation of technological stages in mining. This code is a discrete fracture network (DFN) code that couple geometrical block system construction based on modelisation stochastic with RESOBLOK simulations. The method of three-dimensional modeling (3D) of the fractured rock mass in the quarry is based on the rock mass data, the geometrical parameters of the open pit mine. From there, the rock mass simulation models were used in the analysis of the stability analysis of open pit benches, the optimization of the blast design parameters at overburden benches, project construction materials, and technology projects for block stone extraction. An application in some open pit mines such as quarries of Vietnam is presented.

Binh Thuan province has significant reserves of placer titanium, occupies approximately 92% total reserves of Vietnam. Geological condition of the deposit is quite uncomfortable for mining activities. At present, selection of appropriate mining technology for placer titanium mines in Binh Thuan province is a scientific and practical problem. In this paper, authors researched and developed a selective sequence of appropriate mining technology for placer titanium mines in Binh Thuan province, consists of (1) feasible mining technological schemes, (2) appropriate mining order, (3) possibility of providing water for mine, (4) ensuring slope stability, (5) comfortable alternatives for land rehabilitation and restoration, and (6) high economic effect. With this selective sequence, the appropriate mining technology for placer titanium mines in Binh Thuan province can be selected, and contributes to enhance mining effect, ensures safety and protect environment.