Resilience Integrated Failure Analysis for Hydraulic Lifting System of Deep-sea Mining

A major critical item of a deep ocean mining system is the lift system for elevating the nodules from the collector on the seafloor to the mining vessel on the sea surface. A prime candidate for such a lift system is one which hydraulically transports the material as a slurry through a lift pipe string connecting the collector to the mining vessel. The design and analysis of such a hydraulic lift system necessitates the simultaneous solution of the many interrelated structural, hydraulic, and mechanical aspects of the lift system. Hence, thorough efficient analysis of the lift system can be most expeditiously accomplished through the use of computer analysis utilizing specially developed programs. Computer programs described herein have been developed for two specific types of hydraulic lift systems a centrifugal pump system and an air lift pump system. INTRODUCTION A mining system for mining manganese nodules from the deep ocean floor (e.g., three-mile depth) may be considered to consist of three basic elements:The collection system, for collecting or harvesting the manganese nodules from the seafloor.The lift system, for elevating the collected nodules from the seafloor to the sea surface.The surface system; for operating the previous two systems and for transporting the nodules back to the shore. A prime candidate for the lift system is one which hydraulically transports the nodules as a slurry through a lift pipe string, connecting the collector on the seafloor to the mining vessel on the surface. Because the lift string is suspended in and towed through the hostile, deep ocean marine environment, the lift system is a major critical item, for which thorough design and analysis is imperative. The design and analysis of such a hydraulic lift system necessitates the simultaneous solution of the many interrelated structural, hydraulic, and mechanical aspects of the lift system. Hence, the analysis can be most expeditiously accomplished through the use of computer analysis utilizing specially developed programs. Such computer programs have been developed for specific types of hydraulic lift systems, two of which are a centrifugal pump lift system, and an air lift pump lift system. These two types of lift systems are illustrated in Figures 1 and 2. The centrifugal pump system consists basically of a lift string in which submerged centrifugal pumps are integrally mounted along the lift pipe down to a depth below the critical depth (the depth at which the slurry pressure in the lift pipe would be reduced to zero if there were no pump present in the lift pipe below this depth). The air lift pump system consists basically of a lift string in which compressed air is injected into the lift pipe to effect a pumping action due to the reduced density of the air-entrained slurry. The air must be injected at a depth well below the critical depth in order to effect a pumping action.

1. INTRODUCTION Among the various kinds of deep sea mineral resources, manganese nodules are obviously the most well known and the most explored. Manganese nodules can be found worldwide, but the most promising deposits are located in the Pacific, particularly in the Clarion-Clipperton zone. Economic studies carried out in the past 10 years came to contradictory results regarding the question when to start with the commercial exploitation of manganese nodules, though there is generally no doubt that these resources will be recovered sooner or later. Until then, numerous technical problems are still to be solved, although great research and development efforts have been already made in the past, including deep sea pilot mining operations in 1978. During these operations, two kinds of lifting systems have been tested: Air-Lift and centrifugal pumps. The aim of the following paper is to provide an analysis of the various hydraulic nodule lifting systems. GEMONOD and PREUSSAG decided in 1985 to work in cooperation, especially for the study of the key points:–pick-up device (PREUSSAG)–locomotion of the self propelled miner (GEMONOD)–hydraulic lifting of nodules (PREUSSAG and GEMONOD) 2. MINING REQUIREMENTS 2.1 Definition of an Instantaneous Solid Production An economic analysis of mining nodules shows that the critical annual production for one dredging system would be approximately 1, 5 MT of dry nodules. This means that 2, 2 MT of wet nodules must be collected per year and expected 240/270 operating days a year and assuming full-day production, the nodule mass flow-rate would be 9000 tons/ day. Nevertheless, if we take into account nodule distribution variations at the bottom, crossing slopes, U-turns, transfer to another mining area, ocean and weather condition, unexpected technical failures, etc. (1), it can be shown that a nominal production rate of 500 t/h is required to ensure an annual production of 2.2 MT. 2.2. Maximum Size of Collected Nodules Referring to the table of ore granulometry of the Clarion-Clipperton zone in the North Pacific (figure 1), it may be noted that 95% of the whole nodules are less than 100 mm in size. In theory, it would be possible to reject nodules exceeding 100mm prior to pumping. But if we reduced the maximal collected size to 70mm, 33 percent of the ore would definitely be lost on the sea floor. Thus, the mining system is to be calculated for a maximum size of 100mm. However, the most frequent nodule size is 50mm. 2.3. The Three Methods of Pumping Method A : Whole nodules According to paragraph 2.2., maximum nodule size is 100mm. If we stick to the rule of thumb, which states the diameter of a riser pipe should be 3 times that of the solids to avoid clogging, a 300/330 mm minimum pipe diameter is required, and the spacing S of the pump impeller becomes 300 mm (fig. 2), resulting in an impeller outside diameter of approx. 1.1 m which is far beyond the optimum working conditions of a mining pump, as will be demonstrated in paragraph 4.3 of this paper.

The study aims to analyse the reliability of the main conveyor system in an underground coal mine [Churcha (RO)] in India for estimating the suitable maintenance time. The main conveyor system in the mine has seven subsystems. The present study examined the six common probability distribution functions for fitting the time between failure (TBF) and time to repair (TTR) data. The TBF data in all the cases best fitted with Weibull 3-parameter distribution function except one. But, the TTR data in most of the cases best fitted with Lognormal 3-parameter distribution function. It was found that the subsystems C1, C2, C3, C4, C5, C6 and C7 require maintenance in the interval of 52.39, 65.28, 60.00, 84.66, 98.77, 20.89 and 112.85 h, respectively, to improve the reliability of the system to 80%.

The study aims to analyse the reliability of the main conveyor system in an underground coal mine [Churcha (RO)] in India for estimating the suitable maintenance time. The main conveyor system in the mine has seven subsystems. The present study examined the six common probability distribution functions for fitting the time between failure (TBF) and time to repair (TTR) data. The TBF data in all the cases best fitted with Weibull 3-parameter distribution function except one. But, the TTR data in most of the cases best fitted with Lognormal 3-parameter distribution function. It was found that the subsystems C1, C2, C3, C4, C5, C6 and C7 require maintenance in the interval of 52.39, 65.28, 60.00, 84.66, 98.77, 20.89 and 112.85 h, respectively, to improve the reliability of the system to 80%.

This paper addresses the collection, analysis, and optimization of log data related to the truck haulage system in a mine. After selecting an underground mine in South Korea as the research area, the Mine Production Management System (MPMS) using Bluetooth beacons and tablet PCs was utilized to collect log data related to the haulage system over 18 months. Through the analysis of the collected log data, strategies to enhance the productivity and efficiency of the haulage system were derived. Weekly analysis of log data files was performed, identifying periods with abnormal truck cycle times and conducting an analysis of the underlying causes. It was revealed that the truck cycle time is influenced by the haulage system, equipment operation, and the log data collection system. To shorten truck cycle times and improve the productivity and efficiency of transportation systems, continuous collection and regular analysis of log data and dynamic system and equipment operation based on this are important. Analyzing log data collected over an extended period can help predict future trends in the haulage system and formulate measures and strategies in response. Therefore, it can serve as a valuable decision-making tool for establishing short-term, medium-term, and long-term production and operation plans.

In the construction of offshore platform, because there are many characteristics, such as the heavy weight, large size, high installation height and so on. The hydraulic continuous lifting system is so important for construction. Meanwhile, the lifting system also needs to have good synchronization, stability, security and high efficiency. In this paper, the fuzzy controller is used to control the lifting system. The software interface between AMEsim and Matlab is used to model and simulate the hydraulic system and control system. In the case of lifting weight of 800t, the synchronization and stability of the hydraulic continuous lifting system are analyzed.

In manganese nodule mining hydraulic lifting is one of the methods of conveying the nodules from the ocean floor to the surface. The hydraulic behaviour of such large solids in a tube is different from what we know about small grains and suspensions. This paper deals with the hydraulic behaviour of uncrushed nodules in a tube. Hydraulic behaviour means chiefly: Velocity of the solids, spatial concentration and pressure drop, their interrelation with the water velocity and the diameter of the solids. Tests have been made. In the first series these parameters were investigated with solids of uniform diameter (homogeneous mixtures). The second series dealt with solids of different sizes (inhomogeneous mixtures). Empirical equations based on dimensionless numbers have been established in order to render the test results applicable to larger systems. With the solid velocity and the frictional factors known, the set of equations can be used to compute and design a conveyer system to a high degree of reliability. INTRODUCTION Vertical hydraulic lifting has been used in the mining industry to convey coal iron ore from the pits to the surface.1–5 In marine mining of manganese nodules special conditions area given. International efforts are being made to solve both technical and jurisdictional problems related to this new industry.6–7 The complicated designing procedure for a mining system can be reduced to some simplifying relatives, which are displayed in the "interdependence triangle" of Fig. 1. A production goal for the nodules has been fixed. The reservoir and environmental parameters of the mining site are the main input data. The technical response is given by the installed mining equipment and the mode of operation. This has to be chosen such that the performance and optimization parameters can be computed. The loop is now closed. If one of these corner marks is changed it will affect the others. Two general considerations apply to a mining and conveyer system:The nodules should not be crushed to a greater extent than inevitable in the collector on the ocean floor in order to reduce the dewatering costs on the mining ship.The diameter of the conveyer tube should be kept small in order to reduce the drag of the string in the ocean current. For the designer of a mining system a set of equations is necessary for doing the computer work. Therefore, the hydraulic behaviour of the nodules in the conveyer tube must be known. OBJECTIVE AND TEST PROGRAM It was found in previous studies that the known relations of slurry conveyance cannot simply be transferred to the large solids in question. Therefore, a research program was started in which special attention was payed tothe study of the physical and technical phenomena during the process of conveyance of large solids,establishing empirical equations for the calculation of both the performance and the optimization of a hydraulic conveyer system.

Lifting coarse mineral particles from thousands of meters of seabed to the supportive vessSel is a crucial part of exploitation of deep-sea mineral resources, and the vertical transportation part is a key component of the deep-sea mining system. Three typical vertical transportation schemes are discussed and compared from the aspects of working mechanism, structural scheme, transportation capacity, system efficiency and implementation feasibility in the context of commercial exploitation of deep-sea polymetallic nodules. The conclusion is that the hydraulic pipeline lifting system with a centrifugal pump is a comprehensive scheme. Furthermore, the basic composition and function of the hydraulic lifting system are introduced, and the transportation performance indicators and technical requirements under commercial mining conditions are analyzed. As the key equipment of the lifting system, the structural characteristics, design theory, transportation performance analysis methods and research progress of the lifting pump are described. A 1000 m sea trial was carried out. The lifting system, the tests of the centrifugal pump and the sea trial are introduced.

India is a registered pioneer investor under UN Convention on the law of the sea and has been allotted a mining site in the Central Indian Ocean for exploration and exploitation of manganese nodules, available at depths of 5000m to 6000m in Indian Ocean. To this effect, a joint collaborative programme between National Institute of Ocean Technology (NIOT), India and Institut f/r Konstruktion (IKS) of University of Siegen, Germany was initiated to develop a crawler based deep sea mining system with a flexible raiser. This programme is funded by the Department of Ocean Development, Government of India. Before embarking upon realising the total hardware for deep sea mining, it had become imperative to prove the above concept under shallow water condition at depths around 500m. The shallow water sand mining system consists of crawler, raiser and slurry pumping system, control & instrumentation and the related hydraulic system. The crawler is fitted with traction belts made of rubber, with a large bearing surface area to adequately meet the low bearing pressure of the soil. A manipulator mounted in front of the crawler holds the sand cutter or soil testing apparatus. The mined sand with water is pumped through a flexible hose onnecting the slurry pump and the mother ship. The slurry pump is a reciprocating pump. The entire drive system is obtained through hydraulic motors and actuators. There are two hydraulic systems to supply hydraulic fluid to the drive system and the actuators. The specially designed umbilical cable carries the required power and data to and from the crawler, also takes the load of the crawler and other subsystems. The control signals, transducer data and electrical power transmission are transmitted through this umbilical cable. The sand mining operation is a technology demonstration, envisaged to be deployed for deep-sea mining. The data from this testing would be made use of in validating the design of deep sea mining equipments at depths of 5000m to 6000m. The entire sand mining system costing about DM 5 Million is ready and the sand mining demonstration is expected by the end of 1998. Introduction: India, is a registered pioneer investor under the UN Convention on the law of the sea, and has been allotted a mining site in the central ocean for exploration and exploitation of manganese nodules. India, with a coast line exceeding seven thousand kilometers and with an exclusive economic zone of about two million square kilometers have been involved in the development of technology for deep sea applications since the last decade. India has an ambitious programme on deep sea bed mining for minerals, ocean energy in form of Ocean Thermal Energy Conversion (OTEC), wave energy programmes, and on Remotely Operated Vehicles (ROV) for general off shore surveillance amongst host of other offshore programmes. Though many countries have been showing keen interest to develop the deep-sea nodule mining technology, it has not yet been perfected to the stage of realising a economically viable commercial system despite the enormous efforts on the design and testing of sub-systems. This is mainly due to technological problems and large financial requirements. Hence, India is of the view that a joint development could be the best strategy to develop this technology.

Rubber hose is normally adopted in the connection between the lifting cylinders and the control valves. Low bulk modulus of hose reduces the natural frequency of hydraulic system and brings difficulties to the controller design. This paper focuses on the model simplification of hoses in the hydraulic system. First, a hydraulic lifting system is presented in the paper. Then, simulation model of the lifting system is built in AMESim, and the simplified model of hose is conducted using an improved lumped parameter method. Finally, comparative simulations with the proposed model and the original model provided in the software are carried out. Results show that the simplified model can be used to replace the original model in the simulation of hydraulic systems.

In the open-die forging process, the forging manipulator must cooperate closely with the forging press. Terrible working conditions of open-die forging have resulted in significant demand on the hydraulic control systems of the forging manipulator. This article analyzes the characteristics of major-motion hydraulic systems with the aim of proposing a novel hybrid serial–parallel heavy-duty forging manipulator. Kinematic and dynamic models of the major-motion mechanism are developed to investigate the control and comply with performance of hydraulic lifting, pitching, and buffering systems. Simulation shows that the three hydraulic systems are coupled in the position and posture control of the clamp. A separate posture control method based on the characteristic of the major-motion mechanism is designed for the hydraulic systems, and the position tracking performance of the hydraulic systems is studied in a stretching process of a plat-tool.

Актуальность исследования. Функционирование горнодобывающих предприятий в современных условиях характеризуется активным воздействием факторов внешней и внутренней среды. В условиях нестабильной внешней среды, при переходе от одного этапа разработки к другому, подсистемы горнодобывающих предприятий должны подчиняться цели обеспечения устойчивого функционирования предприятия – обеспечению выходных потоков с заданными параметрами. В этот период изменяется устойчивость горнотехнической системы, что оказывает влияние на состояние экономической и социальной подсистем горнодобывающих предприятий, а также на состояние окружающей среды, вызванное изменениями в параметрах технологии и технологических процессах. Это требует разработки новых подходов и принципов управления работой горнодобывающих предприятий, основанных на согласовании экономических целей с целями в области экологии и социального развития. Цель: разработка концепции устойчивого развития горнотехнических систем в переходные периоды разработки месторождений на основе систематизации существующих принципов устойчивого развития в горнодобывающей отрасли. Объекты: горнодобывающее предприятие, горнотехническая система, система вскрытия карьера. Методы: обзор научной литературы, структурно функциональный анализ, системный анализ. Результаты. Обоснована ключевая роль системы вскрытия в структуре горнотехнической системы для обеспечения целей устойчивого развития горнодобывающих предприятий. Выполнена систематизация принципов устойчивого функционирования и развития горнодобывающих предприятий и его систем с выделением четырех групп принципов: общесистемные принципы управления, принципы развития горнодобывающих предприятий, принципы развития горнотехнической системы, принципы развития подсистем горнотехнической системы. В основу предлагаемой системы принципов положена идея последовательного преобразования подсистем горнотехнической системы на всех этапах проектирования и эксплуатации, учитывающая экономические, социальные и экологические аспекты с целью обеспечения заданных параметров функционирования горнодобывающих предприятий. Предложена концепция устойчивого развития горнотехнической системы в переходные периоды разработки. Использование предлагаемого подхода в период перехода от открытых горных работ к открыто-подземному способу разработки позволяет улучшить экономические, экологические и социальные показатели функционирования систем горнодобывающих предприятий.

Relevance. Long periods of development of steeply dipping deposits necessitate multiple adjustments of mining and technical system throughout an open pit life cycle. The decisions made determine the development strategy of a mining enterprise for a long period. The complexity of making such strategic decisions depends on numerous influencing parameters. These parameters have a different impact, have a variety of units of measurement, target values, and are not only quantitative but also qualitative. There is a need for new approaches to the choice of development strategy of the mining and technical system of an open pit, as well as its main subsystem – the opening-up of an opencast system. It is proposed to base these approaches on multi-criteria decision-making methods that consider many influencing parameters. Aim. Development of a methodology for choosing a strategy for sustainable development of the deep open pit mining and technical system based on multi-criteria decision-making methods and assessment of the opening system parameters. Objects. Mining enterprise, mining and technical systems, opening system. Methods. Literature review, system analysis, multi-criteria decision making. Results. The authors have determined the main strategies for development of the mining and technical system for deep open pits. These strategies aim at achieving the sustainable development of the mining and technical system: adjustment of the current stage mining parameters; transition to a new stage of mining; transition to a combined open-underground mining; mine closure. The key role of the opening system in the structure of the mining and technical system is substantiated to ensure its sustainable development. The authors systematized the main parameters for evaluating the pit opening system and set target values for each parameter. A review of the main multi-criteria decision-making methods used to solve various problems in the mining industry is made. A rank coefficient is proposed for choosing the mining and technical system development strategy. The calculation of this coefficient is based on a combination of the fuzzy AHP and CRADIS multi-criteria methods. A method was developed for selecting a strategy for sustainable development of the mining and technical system of deep open pits. A case study was conducted on the conditions of the Maly Kuibas open pit. The obtained results strongly suggest that the best strategy with the highest ranking is the transition to the combined development method.

During the late 1970s pilot mining tests carried out on manganese nodules in the Pacific and metalliferous mud in the Red Sea demonstrated the technical feasibility of deep sea mining operations. However, the production of manganese nodules on a commercial scale is subject to numerous technical problems. As a result a German/French joint development project has been underway since 1985 into the following key points; nodule pick-up device, locomotion of self propelled collectors, hydraulic lifting of nodules. This paper presents the scope of this R+D program, its main results to date and future prospects. INTRODUCTION Ten years ago deep sea mining, i.e. the production of ore-bearing minerals from the deep sea was at a zenith and enjoyed a large amount of interest worldwide. Spring 1978 saw the first continuous pilot scale production of manganese nodules from the floor of the Pacific ocean (OMI Pilot Mining Test) and May 1979 saw the first production of metalliferous sediments from the floor of the Red Sea (Saudi Sudanese Red Sea Commission, Preussag, Pre Pilot Mining Test).. We now know that these forecasts were incorrect. The start of commercial deep sea mining has moved further away for a number of reasons of which price development in the metal market was undoubtedly one of the more important. This does not mean that development of deep sea mining technologies has ground to a complete standstill. On the contrary; the number of countries in which corresponding research is underway has increased. The USA, Japan, France and Germany have been joined by the USSR, India and Finland. For some years now development work in Germany has concentrated on the development and optimization of critical components and subsystems of deep sea mining techniques, whereby the demand for environmentally non-disruptive production methods has increasingly been taken into account. The following report concentrates on this work where by manganese nodule production technologies represent the major focus. There follows a brief review of the pilot mining tests executed in the late seventies as an outline of the scope of work. BRIEF REVIEW OF PILOT OPERATIONS The first successful pilot mining test on manganese nodules was carried out in 1978 by OMI (Ocean Management Inc.) in which 800 tonnes of nodules were recovered from the floor of the Pacific ocean. This was a joint venture involving American, Japanese, Canadian and German companies (Fig. 1). The mining system comprised:the converted drill ship. SEDCO 445a 5500 m long pipe stringa towed collector Two types of hydraulic lifting systems were tested successfully:an air lift systema pump lift system (multistage mixed flow pumps) Two different nodule collector concepts were tested (Fig. 2):hydraulicmechanical The overall system design had a mining rate of around 30 t/h.

The hydraulic lifting system of 450t schnabel car is more complex variable geometry mechanism. A simple technique for solving variable geometry mechanism is presented. The technique is based on energy conservation principle of hydraulic lifting process. The lifting principle and geometrical models are analyzed and formulated. The lifting pressure is calculated. The static strength design and bulking stability checking are introduced for cylindrical pressure cylinder. Results show that the maximum rated oil pressure meets cylinder lifting requirement, the static strengths of cylinder and piston reach lifting safety and reliability, and anti-bulking stability can be guaranteed under the loading and working conditions.