Green and digital mining method using a system based on a movable automated platform

Abstract

The invention relates to the field of mining, in particular of deposits having average depths of 20 to 100 metres. The invention relates to a new mining method based on opening mining trenches of small widths allowing layers of ore to be accessed directly via a new movable mechanism called a "mining platform". This movable mining platform moves in a straight line along these trenches, receives ore broken from various layers and raises it to the surface. The breaking will be done by a long-wall system. This new operating method attacks ore directly without removal of muck even if the ore is deposited in multiple layers, using a new movable platform and improved long-wall breaking systems. With made-to-measure mining walls that will not require rehabilitation after extraction and because explosives are not used, this new mining method thus overcomes all the environmental constraints and issues raised by other more conventional methods. Digital technology will be integrated into this method at every level. A digital (APC / AI) system installed in the control room will receive and process data delivered by other control systems and will make relevant decisions while ensuring optimal operational performance, satisfactory control of ore quality and optimal equipment reliability. The data will be relayed from the ground by state-of-the-art ore analysers, scanners and sensors integrated into various pieces of equipment. All of the production equipment will be powered with electrical power and will be equipped with control systems based on online sensors and analysers. As the equipment is powered with clean energy (wind, solar, etc.), the mining method will qualify for use in a green mine. Having a better performance, very low operating costs, fully integrating new digital and artificial-intelligence technologies, employing green energy and complying with environmental aspects, this new method may be considered to be the future of medium-depth, smart green mines.

Description

Technical Field The present invention relates to the field of mining exploitation, in particular to medium-depth deposits, including under the constraint of thin seams. More specifically, the invention is a new mining exploitation method that addresses the constraints and drawbacks encountered with conventional mining methods. Based on the opening of a reduced-width trench, this new mining method proceeds to the direct attack of the ore without removal or evacuation of waste material. It thereby makes it possible to achieve the best operational performance indicators (KPIs) of a mining operation. The invention finds application in particular in the mining field, in particular for deposits at medium depths (from 20 to 100 metres), even where these deposits occur in several ore levels (seams). Digitalised at every level (Mining 5.0), addressing all aspects of sustainable development (Sustainability) and thereby proposing a green mine (zero negative environmental impact), this mining invention will enable mining operators to be highly competitive with respect to the following principal indicators: • Production performance • Efficiency • Operating cost (OPEX) • Operational flexibility • Energy consumption • Mine rehabilitation after exploitation Technological Background Mining is the process of obtaining geological materials and valuable materials from the earth. The materials acquired by mining include metals, precious stones, coal, phosphate, limestone, clay, gravel and many others that cannot be produced by agricultural or industrial processes. These materials can only be accessed through mining exploitation that is suitably adapted and economically profitable. There are three principal mining exploitation methods by which various different materials are acquired. The choice of exploitation method is based on its economic profitability and its production capacity. These three (3) principal methods are as follows: Open-pit mining (Open Pit): This is a mining exploitation method that consists in removing the soil and overlying rock above the mineral deposit in order to access the ore (the material extracted). This method is used for deposits whose seams lie close to the ground surface (coal, phosphate, limestone, etc.). Underground mining (Under Ground): This is a mining exploitation method that extracts the ore beneath the earth's surface. The entrance from the ground surface to the underground mine may be created via a horizontal or vertical tunnel (also known as a gallery, shaft or ramp). Underground mining is used when the mineralised body is too deep to be exploited profitably from the ground surface (coal, manganese, gold, etc.). Highwall mining (High Wall System): This is an evolution of the open-pit mining method. It combines the underground and open-pit methods. It is used principally in coal mines. It consists in opening a wide trench alongside the panel to be exploited, then attacking the seams of the panels to be exploited laterally via small sections, while leaving seam pillars to ensure ground stability and support so as to avoid roof collapse. Other particular mining methods also exist, such as the sedimentary or placer method, which is based on a mixture of water / sand and ore (gold, diamond, copper, etc.), and the so-called in-situ recovery method, which has been the principal extraction method for uranium for many years and which consists in the injection of recirculated fluids to which reagents are added, whether alkaline, moderately acidic or acidic. Each exploitation method has its strengths and its constraints. The choice of a given mining exploitation method rests essentially on its techno-economic performance. The principal factor governing the choice of one method over another is the economic aspect, in particular the operating cost of the mining exploitation (“OPEX”). Objects of the Invention The principal objects of the present invention are summarised as follows: • A highly efficient mining exploitation with a greatly reduced operating cost • A selective, flexible mining exploitation with improved grade management • A green mining exploitation having no negative impact on the environment • A highly efficient, automated and digital mining exploitation • A mining exploitation having greatly reduced energy consumption The invention proposes a novel mining exploitation method based on a mechanised winning system using a longwall device and an inventive mobile platform comprising a vertical handling device formed of bucket elevators and belt conveyors. This inventive platform system may also comprise disc screens enabling particle-size separation of the ore, recovering only the good-quality ore while rejecting the waste rock. The production line of this invention can reach an hourly capacity of 6000 cubic metres. This invention further proposes a novel, compact mining exploitation method with a mine layout meeting the geological constraints and data of the deposit, with exploitation panels of identical, custom dimensions. Mining production is selective; the winning of the various grades (seams) is automatic and instantaneous, without planning or mobilisation of equipment, in contrast to the open-pit method. The invention offers a novel mining exploitation method made up of systems and equipment powered solely by electrical energy. These production systems and equipment generate no carbon dioxide (CO2), emit no noise, and do not degrade the terrain after exploitation. With a clean energy supply source, this new method is qualified as being green. The invention also aims to propose a digital, automated mining exploitation method, with remote control, while making use of new digitalisation technologies (5.0) and artificial intelligence. This mining exploitation method operates with a greatly reduced workforce, ensuring only supervision and monitoring of correct operation. The invention also aims to propose a mining exploitation method with greatly reduced energy consumption. Electrical consumption depends on the hardness of the ore to be extracted and is estimated at approximately 1 to 2 kWh / m3. Summary of the Invention The invention is a novel mining exploitation method based on a mine layout into optimised panels and on the opening of central trenches of reduced width. Within these trenches, located at the centre of the panels, a mobile platform is integrated that accesses the various ore seams and translates along this central trench. Ore extraction is carried out by two longwall systems installed to the right and to the left of the mobile platform, which together perform the mechanical winning of the ore across the entire width of the face and convey it directly to the mobile platform, which raises it to the surface. This handling is carried out vertically by bucket elevators integrated in the mobile platform. The principal idea of this mining invention is to attack the ore seams directly without removal or evacuation of overburden or interburden waste. The invention provides continuous, flexible, selective winning with double extraction on two attack fronts separated by the exploitation trench. This double, continuous winning adopted by the invention is achieved by the following principal extraction and handling systems: • Longwall-type winning systems, each system being composed of three pieces of equipment: a double-drum shearer, an armoured face conveyor (AFC) and hydraulic roof support systems. • A mobile platform of metal structure, installed at the level of the exploitation trench, comprising functional equipment such as bucket elevators, belt conveyors and ancillary equipment, and which may also comprise screens depending on the type of ore being exploited. This platform also houses electrical power supply equipment, control and command systems, premises and meeting rooms in its upper part, which is located at the surface. All equipment of this new mining exploitation method operates solely on electrical energy. This production equipment generates no carbon dioxide (CO2), emits no noise, and does not degrade the terrain after exploitation. With a clean energy supply source, this new method is qualified as being green. Digital technology is integrated at every level of this method. A digital system (APC / AI) installed in the control room receives and processes all data originating from the other control systems and makes the relevant decisions, thereby ensuring the best performance and output of the equipment, together with good control over ore quality and improved equipment reliability. Data are transmitted from the field by sensors and analysers. All of the production and handling systems are equipped with control systems based on online sensors and analysers. Control and command of all equipment are therefore carried out remotely and in automatic mode. The operating team is greatly reduced and is stationed in the control room and in the offices located in the upper part of the mobile platform. Operators descend underground only for inspection or for urgent interventions. The descent and ascent of personnel and material is performed by a hoist integrated in the mobile platform. Brief Description of the Drawings The invention, together with the various advantages and strengths that it presents, will be readily understood with the aid of the description of the figures and the details that follow: Description of Figure 1: Implementation of the Method Figure 1 illustrates the various phases in the implementation of this method, from the studies and set-up of the method through to the exploitation phase. Implementation of this new mining exploitation method thus proceeds through 3 phases, summarised as follows: Phase 1: Mine layout and preparation of the panels This is the study and ground preparation stage, which consists in carrying out a mine layout, defining the overall exploitation scheme, defining the panel dimensions, the face widths and the trench widths. It also consists in marking out and opening the trenches. This phase proceeds through the following steps: • Definition of the dimensions of the mine panels and exploitation faces (3D, 3G) •  Opening of the exploitation trenches (5), project trenches (7) and edge trenches (6). Phase 2: Project phase and installation of the exploitation equipment This is the project phase. It consists in installing the various items of platform (1) equipment and the longwall exploitation equipment (2). The longwall equipment (2) is installed at the level of the project trenches (7), facing the seams to be exploited. The platform elements are assembled at the level of the exploitation trench (5), in particular at the starting point facing the longwall equipment (2). The steps of this phase are as follows: • Assembly and installation of the elements and sub-assemblies of the platform equipment • Assembly and installation of the longwall equipment. Phase 3: Start-up of mining exploitation This phase consists in starting up the longwall exploitation equipment and the mobile platform, and commencing exploitation. It proceeds through 2 steps: • No-load and load testing of the platform and longwall equipment. • Start-up of mining exploitation on the 1st panel, with 2 attack fronts, after which the operation moves to the other panels following inspection and mobilisation of the equipment. Description of Figure 2: Principle of the Method Figure 2 presents an overall description of the method during the exploitation phase. It shows the panels and faces prior to exploitation (3D, 3G), the panels after caving (4D, 4G), the exploited and caved panels (8), and the panels reserved for future exploitation (9). This figure also shows the exploitation trenches (5), which divide the panels lengthwise, the project trenches (7), located ahead of and behind the panels, and the so-called separation trenches (6), located at the two edges of the panels. Figure 2 also presents the mobile platform system (1) introduced at the level of the exploitation trench (5) and the two longwall winning systems (2). It further explains the direction of mine advance, and the right-hand exploitation face (3D) and left-hand exploitation face (3G) of the panel. Description of Figure 3: Identification of the Equipment and Systems Figure 3 shows the detail of the systems and equipment of the mobile platform and of the longwall units, as well as a cross-section through the geology of the deposit showing the various seams to be extracted. This figure shows that the mobile platform (1) is constituted by a metal structure, a translation system (1H) enabling advance of the platform, bucket elevators (1A), a disc screen (1B), screened-ore conveyors (1C) and (1I) feeding directly into an adjacent mobile conveyor (1J), waste conveyors (1D) and (1E) feeding an adjacent mobile waste conveyor (1K), guide wheels (1F), and lateral skids (1G) installed on either side of the platform (1) to ensure platform stability. Figure 3 further shows that the longwall winning systems (2) are constituted by double-drum shearers (2A) enabling continuous winning, a haulage mechanism (2D), armoured face conveyors (2B) and hydraulic roof supports (2C) enabling roof support and advance of the longwall mechanisms. This figure also presents a geological cross-section of the ore showing the detail of the various ore seams (11), the overburden waste material (10), and the interburden (12) separating the various ore seams. Description of Figure 4: Detail of the Equipment and Systems Figure 4 gives the detail of the various compartments of the upper part of the platform, located at the surface, and describes the vertical arrangement of the longwall units (2) relative to the platform (1), as well as the detail of the auxiliary equipment integrated in the mobile platform (1). This figure also shows the conveyor handling block diagram referred to in Figure 3, and the detail of the control room (1N), which houses the principal automation and digital systems. These command and digitalisation systems are composed of a highly advanced centralised digital system (APC), which is fed by the following other systems: • Process command and control system for the entire method (DCS) • Geological ore stock monitoring and control system (SMS) • Condition-based maintenance monitoring and control system (CMS) • Energy monitoring and control system (PMS) This control room also comprises automation and digital cabinets, an ergonomic screen display system enabling the display of operational data and performance indicators (KPIs), a meeting room and offices. This figure also shows that the mobile platform (1) contains an electrical room comprising an electrical substation fed by a cable-reeling system and composed of electrical transformers, variable-speed drives and electrical switchboards. It further shows that the mobile platform (1) houses auxiliary equipment, utilities, a hoist (1M) and stabilising skids for the trench walls and the platform (1K). This figure also shows that the longwall systems (2) are arranged vertically one above the other and are constituted by shearers (2A), hydraulic supports (2C) and armoured face conveyors (2B), and that these armoured face conveyors are aligned with the bucket elevators, thereby ensuring their supply with the won ore. Description of Figure 5: Digitalisation System Figure 5 gives a detailed explanation of the overall architecture of the digitalisation and controlcommand system for the entire set of mining equipment of this new exploitation method. It presents the overall digitalisation diagram, from the lower (field) level up to the upper level, which concerns data processing, commands, display of performance indicators and selfimprovement of the parameters of the mining production system. This figure shows that digital technology is integrated in this new exploitation method at every level: Field level (lower level): Equipment This level of digitalisation is of the hardware type. It is installed on the functional and auxiliary equipment. It is composed of sensors, junction boxes (JB) and remote input / output modules (RIO): Sensors: All equipment is fitted with powerful sensors and analysers that measure physical parameters and report the relevant information. These sensors may be classified according to the type of data they report: • Ore grade and quantity sensors: installed on the platform walls and on the longwall shearers (X-rays, gamma rays, etc.) and volume scanners. • Equipment operation sensors: installed on all equipment, of the position controller, rotation controller, encoder, GPS, speed sensor, level sensor type, etc. • Maintenance and equipment health sensors: installed on all equipment, of the temperature probe and controller, vibration analyser, oil analyser type, etc. • Energy sensors: in addition to electricity meters, supplementary sensors are installed on all electrical consumers (motors, lighting fixtures, etc.) • Safety sensors: installed on all equipment, of the smoke detector, gas detector type, etc. • Cameras: installed at all critical points of the equipment, such as winning points, ore discharge points, etc. Junction Boxes (JB): As shown in the diagram, the sensors are connected to junction boxes (JB), which provide protection, simplify cabling and ensure cable identification. Remote Input / Output Modules (RIO): These are Remote Input / Output (RIO) modules connected to the JBs, of analogue and digital types. They receive input signals and transmit outputs in the form of commands to the various equipment actuators. Server level: Server room This level of digitalisation takes place at the level of the server room, which hosts the process databases and the control systems (DCS, SMS, CMS, PCS), with control redundancy, one primary and one secondary (Controller 1, Controller 2). This control level manages and supervises all operations of the entire set of equipment of this new method. Upper level: Control room This level of digitalisation is of the software type. It is made up of 2 levels: An upper level comprising a highly advanced digital system, the APC (Advanced Process Control), and artificial intelligence, AI (Artificial Intelligence). This level of digitalisation relies on databases and machine-learning algorithms with the aim of optimising performance and providing improved, dynamic supervision of the process of this new method. A higher level of overall operational control of the method's equipment, comprising the following four control systems: • SMS: Stock Management System, connected to the server room. It enables the location, management and tracking of ore-seam data in terms of grade and quantity. • DCS: Distributed Control System, connected to the server room. It provides control, command and supervision of the various systems and equipment of the mining exploitation method. • CMS: Condition Monitoring System, also connected to the server room. It provides monitoring of the maintenance and health status of the equipment of this method. • PCS: Power Control System, also connected to the server room, enabling monitoring and control of the energy consumption of the various equipment of this mining method. Data processed by the command systems (SMS, DCS, CMS, PCS) are transmitted to the advanced system (APC / AI), which provides dynamic processing of the various mining exploitation parameters of this new method with the aim of: • Optimising equipment output • Achieving the best performance indicators (KPIs) • Improving final ore quality by reducing variability and improving flexibility • Optimising the energy consumption of the equipment Detailed Description of the Invention : The core of this new method is the direct and continuous attack of the ore seams, commanded from the surface, without evacuation of overburden and interburden waste material, by way of trenches and by means of mobile extraction and handling systems. This new method consists in opening trenches enabling a mobile platform to be housed and the various ore seams to be accessed. Winning in this new method is carried out on 2 parallel fronts by 2 longwall systems, whose reliability and performance have been demonstrated in underground mines. As shown in the figures, this invention is based on a mobile platform equipped with vertical and horizontal handling systems, a screening system and auxiliary equipment. This platform translates along an exploitation trench, receives the ore extracted from both sides by the longwall units, and raises it to the surface. The mobile platform systems and the longwall systems are enhanced in this new method by the latest digitalisation and artificial-intelligence technologies, so that command and supervision are automatic, remote and autonomous. In this new method, the operating personnel provide only supervision in the control room and descend to the underground levels only for inspection or in the event of urgent interventions. The descent of operators and materials is performed by a hoist integrated in the platform. Indeed, after the geological studies have been carried out, application of this new method proceeds through a geotechnical study and a mine layout enabling preparation of the ground. Once these ground and preparation studies have been finalised, sizing studies are carried out for the longwall winning equipment and for sizing the mining platform and its vertical and horizontal handling equipment. Mine layout and ground preparation : This section gives the overall scheme of this mining exploitation method. Indeed, before commencing the project of setting up the method, a preliminary study is carried out, making it possible to perform an optimised layout into several adjacent panels of identical dimensions, separated by trench openings. The object of this study is to determine the panel dimensions, the widths of the exploitation faces, and the dimensions of the various trenches. Panels and exploitation faces : In this new method, the panel dimensions are determined on the basis of the mean time between failures of a longwall machine and the lengths of the winning faces. The two ends of the panels, front and rear, are the two project trenches, intended for the assembly and disassembly of the longwall machines, for maintenance, or for moving on to adjacent panels. The mean time between failures (T) is approximately 2 years, after which the sub-assemblies of a longwall unit are dismantled and overhauled under scheduled maintenance. The widths of the winning faces (l / 2) correspond to the lengths of the longwall machines. Over the 2 years of operation, the machine will travel, on average, a distance (L), determined according to the nature and hardness of the ore. In this method, this length corresponds to the average length of a panel. • Mean time between failures (T) = approximately 2 years • Panel length (L): distance travelled during period T. • Face width (l / 2) = length of the longwall machine. The exploitation panels in this new method are calculated as follows: • Length (L) = distance travelled by the machine during period T. • Panel width = (2 x face width (l)). Generally, for significant production exceeding an hourly capacity of 5000 cubic metres, using long longwall machines of approximately 500 metres in length, the panels may be limited to the following dimensions: • Panel length L: 5000 metres • Panel width l: (2x500) metres. For an average hourly production of 1000 cubic metres, the panels may be limited to the following dimensions: • Panel length L: 2000 metres • Panel width l: (2x100) metres. Trenches The dimensions of the trenches opened depend on the dimensions of the equipment to be accommodated, the panel dimensions, the depth of the last seam, and also the production capacity to be achieved. Exploitation trench (5): The dimensions of the exploitation trenches (5) are determined according to the width of the mobile platform (1), the length of the exploitation panel, and the depth of the last seam to be exploited: • Trench width (5) = width of the mobile platform (1) + 0.6 metre • Trench length (5) = length (L) of the exploitation panel • Trench depth (5) = depth of the last seam + 5 metres. The width of the mobile platform is related to the production capacity, the nature of the production, with or without screening, and the number of lines. Generally, a width of 12 metres is sufficient for a platform comprising a single production line with screening: the exploitation trenches therefore require minimum widths of 12.6 metres. Project trench (7): As explained above, this trench provides for the assembly, installation and disassembly required to move on to the other faces. The dimensions of the project trenches (7) are determined according to the dimensions of the sub-assemblies of the longwall machine (2), the panel width and the depth of the last seam to be exploited: • Trench width (7) = 12.6 metres. • Trench length (7) = width (l) of the exploitation panel • Trench depth (7) = depth of the last seam. At the end of exploitation of a panel, this trench (7), located at the end of the panel, enables the longwall equipment (2) and the platform (1) to be removed. After a panel has been exploited, the platform is separated into sections of 12 metres on each side and is withdrawn into the project trench so as to be moved and installed in the next exploitation trench. Isolation or edge trench (6): Located at the two edges of the panel, this trench serves only to separate the panel being exploited from the other panels so as to ensure controlled and instantaneous caving. The length of the separation trenches (6) corresponds to the length of the panel. The depth of the separation trench (6) corresponds to the depth of the last seam. The width, however, must be kept to the minimum possible: • Trench length (6) = width (l) of the exploitation panel •  Trench depth (6) = depth of the last seam. •  Trench width (6) = 0.2 to 0.3 metre According to current trenching technologies, widths of 0.2 to 0.3 metre are technically achievable at medium depths. Characteristics of the trenches : The marking-out and siting of these trenches must be carried out by a surveyor. The opening of these trenches must be carried out using special machines, such as trenchers, milling machines, planers or surface miners. The use of explosives or of materials that degrade the hardness and stability of the ground and trench walls is to be avoided in these excavation works. After opening, the two lateral walls must be characterised by: • Surface flatness: ± 200 mm • Parallelism of the two surfaces: ± 200 mm After opening the trenches, if the ground walls are not stable, it is necessary to stabilise these walls using stabilisation techniques known in the art. The floor of the exploitation trench (5) must have acceptable strength and bearing capacity in order to support the weight of the mobile platform. Production systems and principal equipment This part of the invention is based on 2 essential systems: the longwall winning system and the mobile platform system. Longwall system: The winning system used by this new method is longwall winning. This winning system is widely used in underground mines, and particularly in coal mines. It is a winning system that has proven its performance, its low costs and its reputation in coal mines in recent years. This new method works simultaneously with 2 longwall units in parallel on the 2 fronts on either side of the mobile platform. Principal equipment of the longwall unit: In this new method, the 3 essential components of a longwall unit are used: • A double-drum shearer • An armoured face conveyor (AFC) • Hydraulic roof supports In addition to the digital technological advances installed in this equipment, the shearers installed in this new method are equipped with online material analysers and scanners that analyse and transmit ore-quality data to the digital system (APC / AI) prior to winning, with a view to making a decision as to the grade to be produced. All of the equipment of this machine is fitted with sensors and analysers of the latest generation. Advantages of using the longwall unit: This longwall winning system has been adopted in this new method in order to benefit from the following advantages: • Mobility, remote control and automatic roof support • Continuous winning with improved performance • Reduced particle size of the extracted ore (0 to 90 mm) • Use of electrical energy Mobile platform system: The mobile platform system represents the core of the invention of this new method. Without this mechanism, this method could not be applied. This platform is the means by which the link is established between the underground ore seams and the surface. It comprises the following equipment and systems: • A metal structure (chassis) called the mobile platform (1), which supports and houses the entire set of operating systems, ancillary equipment and command equipment • Two bucket elevators (1A) integrated in the mobile platform (1) • A translation system (1H) ensuring mobility of the platform (1) • A rotary disc screening system (1B), optionally • Belt conveyors (1C), (1J), (1D) and (1E) • Two hoists (1M) • Roller guide systems (1F) • Stabilising skids (1G) • A power supply station and electrical room (1L) • A control and command room comprising command systems (SMS, DCS, CMS and PCS) and a centralised, advanced digital system (APC / AI) As explained above, this mobile platform contains at least 2 bucket elevators that transport the ore vertically to the surface, feeding a screen or a conveyor depending on the option chosen. This mobile platform can operate in two options depending on the application and the type of ore: • Option 1: With screening of the ore • Option 2: Without screening of the ore Option 1 concerns a rotary disc screening system (1B), which may be installed at the top of the mobile platform (1) and which may be fed directly by the two bucket elevators (1A), thereby providing screening of the ore prior to conveyance to the processing plant, so as to avoid transporting waste material. Option 2 consists in conveying the ore directly to the processing plant by means of mobile belt conveyors installed alongside the platform. Operating mode of the method As explained in the description of the various figures, and following start-up, winning of the mining panel is carried out on 2 fronts, a right-hand front and a left-hand front of the platform. Indeed, the number of longwall units installed is double the number of ore seams. Facing each seam, 2 longwall units are installed (one machine per front). The installed longwall units must be arranged vertically one above the other. The two longwall units (2) installed at the same level have automated synchronisation and must operate in parallel, thereby enabling the winning of ore from the same seam in order to ensure the same production grade. These winning systems (2A) feed the armoured face conveyors (2B), which convey the extracted ore to the bucket elevators (1A) of the mobile platform (1). These elevators raise the ore to the surface. Extraction is carried out in a single pass of the pair of longwall units installed at the same level. Winning begins with the first (uppermost) seam level and proceeds downward, alternating among the various installed pairs of longwall units. Once the first ore level has been won by a winning pass, the pair of longwall units at that level stops, and the next pair, at the 2nd level, starts. Control is carried out automatically and remotely. These operations are repeated in alternation down to the last ore seam level. During winning by the longwall units, the platform is immobilised in translation (in braking mode), but the bucket elevators remain in operation, allowing the won ore to be raised to the surface. The mobile mining platform (1), introduced into the exploitation trench (5), receives the ore conveyed by the two armoured face conveyors integrated in the two winning systems (2) on both sides, and raises it to the surface by means of bucket elevators, feeding a disc screen or a belt conveyor (where the application does not require screening). The ore passing through the screen is conveyed by the belt conveyor (1C) to the feed conveyor (1I), which feeds a mobile, crawlermounted belt conveyor (1J), enabling the screened ore to be transported to the link conveyors, thereby feeding the screened-ore stockpile at the processing plant. The screening reject (waste material) is conveyed to conveyors (1E) and (1K), enabling the discharge and storage of waste material behind the platform, for backfilling of the trench or of the exploited and caved area, while avoiding its transport off-site. After winning of the last ore level, all pairs of longwall units are stopped, which allows the platform and the systems of all the pairs of longwall units to advance by a step of approximately 200 to 500 mm, which may be improved upon. This step advance of the mobile platform is ensured by the translation system installed at the base of the platform. Advance of all of the longwall systems is achieved by the ram systems installed on the hydraulic supports. Advance of the longwall units must take place simultaneously and must be synchronised and well controlled. Mobility of the overall system is ensured by a cable reel installed on the platform, which must have a cable-length capacity corresponding to the overall travel of the platform and of the longwall machines. This cable reel, fed by the medium-voltage electrical network, supplies the electrical room of the platform. This electrical room supplies electricity to the entire set of functional and auxiliary equipment of the platform and of the longwall units. After this advance of the platform and of all the longwall units, a new extraction cycle is triggered and winning recommences, always from the 1st seam level. After each advance, the right-hand and left-hand skids of the platform press against the two trench walls, thereby ensuring stability and verticality of the platform and of the bucket elevators. After the advances, the overburden and interburden waste material located above the roof falls into the voids created behind the hydraulic supports. The void created at the surface is filled by the waste material rejected by the disc screening systems. These operations continue automatically until winning of the seams of the current panel is complete. After exploitation of the current panel, the longwall equipment and the platform are mobilised and installed at the adjacent panel, following inspections and scheduled maintenance actions aimed at ensuring the reliability of this equipment for the next exploitation cycle. Maintenance of the entire set of platform and longwall equipment is scheduled at the end of exploitation of each panel (approximately every 2 years of operation). Inspections and maintenance operations must be carried out by specialists (preferably the manufacturers of these machines) under a maintenance contract. Advantages and Strengths of the New Method : In contrast to conventional mining methods (open-pit, underground, highwall, etc.), this new method presents several advantages, both operationally and in terms of sustainable development. These advantages may be summarised as follows: Improved efficiency and operational performance (Mining efficiency): • Improved production capacity per line (more than 6000 m3 / h) • Improved overall equipment effectiveness, estimated at 90 to 95% • Greatly reduced operating workforce (9 to 12 persons) • Greatly reduced production cost (OPEX), estimated between 60 and 80 MAD / m3, depending on ore hardness and seam thickness. • Greatly reduced energy consumption (1 to 2 kWh / m3). Very good production flexibility for different grades, with discharge of waste material (tailings) into voids created within the mine (Mining flexibility) No negative environmental impact (Mining Sustainability): • Zero CO2 emissions • Zero noise nuisance associated with the use of explosives • Zero waste rock and overburden after exploitation Full integration of digital technology at every level (Mining 5.0) NB: These figures are estimated and calculated on the basis of medium-hard ore rock having average mechanical strengths of approximately 10 to 25 MPa in terms of Young's modulus (longitudinal modulus of elasticity).

Claims

Claim 1A mining exploitation method, characterised in that it comprises the marking-out and opening of 3 trenches having depths greater than the depth of the last seam, defined as follows:- an exploitation trench (5) located at the centre of the panels in the lengthwise direction and separating the panels into 2 fronts;- a panel isolation trench (6) located at the lateral sides of the panels;- a project trench (7) located upstream and ahead of the panels.Claim 2A mining exploitation method according to claim 1, characterised in that it comprises a mine layout into panels of identical dimensions, wherein:- the lengths are related to the mean time between failures of the equipment (T);- the widths are equal to the widths of the 2 fronts plus the width of the trench (5).Claim 3A mining exploitation method according to any one of the preceding claims, characterised in that the trenches have frontal surfaces (walls) that are finely finished, rectilinear, well aligned and parallel (parallelism and flatness of the surfaces: ± 200 mm).Claim 4A mining exploitation system, characterised in that it comprises a vertical ore-handling device, called a mining platform, of metal structure, further comprising the following equipment:- two bucket elevators integrated in the mobile platform;- a translation system ensuring mobility of the platform;- belt conveyors;- auxiliary and ancillary equipment;- a control and command room comprising a centralised digital system (APC / AI) together with other process control systems (SMS, DCS, CMS, PCS);- an electrical room;- offices.wherein said platform may comprise a screening system depending on the nature of the ore.Claim 5A mining exploitation system according to claim 4, characterised in that it comprises winning devices, called longwall units (2), having double-drum shearers or ploughs, armoured face conveyors (AFC), and hydraulic roof support and advance systems, wherein said longwall systems are arranged vertically one above the other.Claim 6A mining exploitation system according to claims 4 and 5, characterised in that it comprises a mobile platform (1) comprising two bucket elevators (1A), wherein each bucket elevator has a plurality of feed points corresponding in number to the seams to be exploited, said two bucket elevators integrated at the level of the mobile platform enabling the ore to be transported vertically to the surface, feeding a screen or a conveyor depending on the option selected.Claim 7A mining exploitation system according to claim 4, characterised in that it comprises a translation mechanism (1H) supporting the chassis of the platform, enabling the platform system (1) to advance for a new exploitation cycle, wherein said translation system (1H) may be constructed according to one of the following 3 options:- rails;- motorised crawler tracks;- motorised tyres.Claim 8A mining exploitation system according to claims 2 and 4, characterised in that it comprises a mobile platform (1) operable according to two options:- Option 1: with screening of the ore;- Option 2: without screening, directly to mobile conveyors.Claim 9A mining exploitation system according to claim 4, characterised in that it comprises a mobile platform (1) that is stabilised at rest after stopping in translation and prior to commencing an exploitation cycle, by the following devices:- a braking device installed at the level of the translation systems (1H);- stabilising skids with hydraulic rams, installed on the 2 lateral sides (right and left) of the mobile platform, thereby providing stabilisation thereof.Claim 10A mining exploitation system according to claim 4, characterised in that the systems and equipment operate solely on electrical energy, wherein an overhead electrical line, aligned with the trench (7), in front of the panel to be exploited (3G / 3D), supplies the electrical substation at the level of the electrical room (1L) via an electrical cabinet and a cable-reeling system whose cable-length capacity corresponds to the overall travel of the mobile platform.Claim 11A mining exploitation system according to claims 4 and 5, characterised in that it comprises reliable sensors installed at the level of the equipment, wherein sensors of the ore-analyser and scanner type capture and transmit reliable information on the grade and quantity of ore per seam, and wherein other sensors are installed on all of the equipment, reporting the full set of operational, maintenance, safety and energy-consumption data.Claim 12A mining exploitation system according to any one of the preceding claims, characterised in that it comprises a highly advanced centralised digital system (APC / AI) installed in the control room, which relies on databases and machine-learning algorithms with the aim of optimising performance and providing improved, dynamic supervision of the process, so as to achieve the best performance indicators of this new mining exploitation method, wherein said centralised digital level is fed by command and control systems (DCS, SMS, CMS, PCS) installed in the control room and server room, which control and supervise all operational aspects of this new exploitation method.

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