Modeling of a bucket wheel dredge system for offshore sand and tin mining

The purpose of this dissertation is to create a computer simulation model of a bucket wheel dredge for mining sand and tin-ore. This research is part of a long term plan of PT Timah Tbk, an Indonesian tin mining company, to search for alternative dredging technologies for offshore mining of tin-ore in 50-m depth or deeper.; The model is based on the understanding of the soil cutting process and fundamental laws governing hydraulic transport including the solids effect on the pump and variations of energy balance equation. It gives satisfactory results when verified with the experimental data and compared with another available model. It is concluded that the bucket wheel dredge (BWD) model is an accurate and effective tool for simulating the dynamic behavior of a bucket wheel dredge system. It possesses the capability of describing the phenomenon displayed during the dredging operation. It can be used as a support tool for planning a dredging operation or designing a dredge. The model is also capable of guiding the users in designing a dredge and to determine the suitable operating parameters for the dredging operation. The additional capabilities include the ability to identify the compatibility of bucket wheel dredge components and to calculate the number of required pumps for a certain dredging operation.; One part of this research investigates the physical properties of tin-ore taken from three different locations in the vicinity of the Bangka Island in Indonesia. Results show that tin-ore has essentially the same properties as sand, non-cohesive, and its properties are in the same range as regular sand, except for specific gravity (SG_s = 4.08–4.39).; The investigation shows that the most suitable system for the tin mining operation in deeper water is to employ a hydraulic transport only in the part of lifting tin-ore from the ocean floor to the surface. The rest of the system uses barges to transport the tin-ore to the inland plant, which is similar to the current system.