TOTAL RECORDABLE INJURYFREQUENCY RATE
The total recordable injury frequency rate (TRIFR) is calculated by multiplying the number of recordable injuries occurring during the year by 1,000,000, divided by the number of hours worked at Koniambo Nickel, including the hours worked by its contractors, during the same year.
We use this indicator as a measure of our progress in reaching our goal of “Zero Harm”. The TRIFR includes all injuries requiring medical treatment at a minimum. The TRIFR helps us track Koniambo Nickel's safety performance and compare our performance with the nickel industry overall. The lower our TRIFR, the better Koniambo Nickel's safety performance. The rate published on this site is updated at the beginning of each month.
A brief description of the cutting-edge technologies we use at Koniambo Nickel’s industrial complex, with an ore processing flowchart, from extraction to export.
DRILLING AND MINE MODELLING
Ferronickel production begins well before ore is taken from the ground. It all starts with drilling campaigns and mine modelling. Core samples are drilled in tight grid patterns, and the collected samples are analysed in a laboratory and the results are fed into Koniambo Nickel’s database. The collated data is used to generate a model that depicts the ore deposit in three dimensions, along with cartographic references. At this stage, the “estimated reserves” are calculated. Converting reserves into resources also involves conceptualising the open-pit mines, as well as the haul roads, related infrastructures and waste-rock impoundment sites needed for a mine to operate.
Operations are then begun the various mine faces. The first step involves removing the overburden (topsoil). This overburden material is set aside and kept for the site’s future rehabilitation and revegetation. The next step involves mining the rock and selectively separating mineralised rock (ore) from rock containing no minerals (waste rock), which is considered to be not marketable. The waste rock is hauled away to an impoundment site.
ORE EXTRACTION AND PROCESSING
Ore is excavated by hydraulic shovels, transported by truck and unloaded into a hopper at the Ore Preparation Plant. To ensure the shovels are digging in the right places, a regular grid pattern is used for taking samples at the mine faces, which is done every shift. The teams regularly shoot explosives (relieving shots) to weaken the ore for better access, especially when mining in an area where the rock is largely intact. The extracted material is then hauled in 100-tonne trucks, called dumpers.
The ore is trucked to Koniambo Nickel’s Mine Industrial Area (MIA), which is the mine’s nerve centre, which includes a maintenance facility, a command and control post for heavy-equipment operations, and an Ore Preparation Plant, where the ore is sorted. Koniambo Nickel’s mine operates twenty hours per day, three hundred days per year.
The Ore Preparation Plant sorts the extracted materials into three categories: earthy materials, ore with Nickel content and unaltered waste rock. The material rejected by the sorting process is recycled for use in environmental protection or construction of haul road infrastructures (such as berms, water management structures, rock fill, and waste dump consolidation).
Every year, the Ore Preparation Plant will produce 3.3 million tonnes of wet ore to be carried to the Metallurgical Plant for processing. To produce this amount of ore, 25 million tonnes of material (ore and waste rock) will have to be extracted from the open pit mines.
The Overland Conveyor carries the wet ore from the Mine Industrial Area to the wet ore stockpile platform at the Vavouto Industrial Area. The conveyor is 11.8 kilometres long and has two sections. The conveyor moves the ore at a speed of 4 metres per second.
At the Vavouto Industrial Area, the ore is stacked into piles by means of an ore stacker that rides back and forth along a railway track, laying the ore down in successive strips to ensure a good blending of the incoming ore and thus limit any adverse effect that swings in ore quality would have on the operation of the metallurgical furnaces. From there, the ore is moved by conveyors to the Metallurgical Plant.
Ore inventory is stockpiled at four platforms: there are two main platforms with room for 60,000 dry tonnes each, and two back-up platforms with room for 25,000 dry tonnes each. Ore is moved and fed into the Metallurgical Plant seven days a week.
Since 1 April 2015, Koniambo Nickel has been using an on-line analyser to obtain authoritative data on the chemistry of the site’s ore product.The on-line analyser, comprising a controlled neutron analyser (CNA), is a system that analyses the chemical composition of ore in real time as it is stockpiled at the Metallurgical Plant. The system provides Koniambo Nickel with a real-time, reliable, accurate chemical analysis of the ore arriving from the Ore Preparation Plant (OPP).Reliable, live data permit quantifying and optimising the blend of the ore before it is fed into the Metallurgical Plant’s NST process, as well as improving the quality of the ore sourced at the Mine and thus the extraction of nickel.BackgroundIn 2008, Koniambo Nickel began talks with EADS-SODERN, a global leader in the field of chemical analysis.On 18 October 2013, Koniambo Nickel began to use the CNA technology after a comprehensive commissioning process.After that, until late March 2014, the technology underwent several successive calibration phases which involved comparing CNA results against dynamic sampling results for the same ore production; SODERN also contributed its expertise in this field of highly complex calculations.Since 1 April 2015, Koniambo Nickel has been using the CNA to obtain authoritative chemical data on the chemistry of its ore.The technologyWith a source of radioactive neutrons whose emission can be controlled by adjusting the electrical current, this technology permits both the immediate cessation of radioactive emissions (unlike the continuous emission radioactive sources) and a highly detailed analysis of the entire volume of ore given the highly penetrating power of neutrons. The method, called Pulsed Fast and Thermal Neutron Activation (PFTNA), bombards, in a controlled manner, all the ore with very high kinetic energy neutrons for a few milliseconds, then measures the induced radiation emitted from the ore while the source is shut off for a few milliseconds, and so on. This method considerably reduces background noise and overcomes the problems associated with changes in ore flow, ore chemistry, mineralogy and so forth.Recalibration at a reasonable frequency and comparative tests with an analytical laboratory are sufficient to ensure the measurement quality.More than 200 CNAs are currently in operation worldwide.Koniambo Nickel has also decided to install the most recent model of CNA, the CNA™ EVOLUTION, with which SODERN has considerably improved the neutron production costs, data processing, and design by reducing the volume of radiation protections without compromising safety.Used dailyKoniambo Nickel now obtains the chemical characteristics of its ore with the CNA.The system can detect irregularities in the ore selection and preparation processes; for example, a sharp, unexpected variation that persists in the ore chemistry is a very reliable indicator that something is not right. The CNA can thus be a very responsive tool for identifying and correcting irregularities.The CNA is also used to ensure the optimal chemical characteristics of the ore entering the Metallurgical Plant: because there is next to no lag in knowing the ore grade, the adjustment of a stockpile’s final chemistry is greatly facilitated and highly reliable.The on-line analyser now requires little more than routine maintenance and the relatively undemanding regular monitoring of its performance.
MILLING AND DRYING
At the milling and drying facility, the wet ore from the blending platforms is ground down to a grain size of less than 1mm and dried until its moisture content is less than 1%.
More specifically, the wet ore is fed by gravity into the mill, where a hammer mill reduces its grain size. It is quickly dried while being moved upward inside a flash dryer, being helped along by a flow of hot gases produced by a coal-fired electrical power generator.
The dust carried along by the drying gases must be recycled, as is the case for the dust produced by the calcining unit.
To prepare the ore for processing at the next unit, the hammer mill flash dryer must also heat the ore from 25°C to 160°C and produce an inventory of dry ore in case the unit is shutdown, to avoid disrupting the ore feed into the calciner.
The calciner serves two major purposes:- to provide the energy needed to evaporate the crystalline water chemically bound to the ore and - to provide the energy needed to increase the ore’s temperature to about 1000°C so as to keep the temperature in the Fluid Bed Reducer at 920°C.
The dry ore from the flash dryer is fed into the calciner using a pneumatic conveyor or lift. At this point, the dry ore still has 11% moisture content by weight, and the flash calciner eliminates this water. Inside the calciner, hot gases are mixed with the preheated ore. The calciner also has several cyclones for pre-heating the ore and for separating gases from solids.
The primary purpose of reducing the ore is to partially reduce the volume of iron oxides and thus remove oxygen in preparation for smelting.
The ore from the Calciner flows by gravity into the Fluid Bed Reducers, where iron oxides and nickel are partially reduced (the beginning step in transforming ore into metal) by means of hot gases and pulverized coal. The finest ore particles are heated to about 925°C so as to prepare them for smelting (the next step).
Smelting occurs in an electric furnace heated to 1600 degrees, and ferronickel is periodically tapped into ladles.
As for the slag, it is tapped continually at 1600°C into 30 m3 slag pots and hauled to the slag disposal area.
Fresh water in a closed-circuit system cools some parts of the furnace. The NST technology is designed to contain all the dust and achieve state-of-the-art environmental performance in terms of atmospheric emissions and energy efficiency.
An overhead travelling crane transports the ferronickel from the smelter (the last stage in the NST process) to the refinery.
Refining involves eliminating the sulphur from the ferronickel. This takes place in desulphurising furnaces. The refined ferronickel is transported by overhead travelling crane to the shotting unit.
The role of the shotting unit is to produce fragments of refined ferronickel for storage in containers prior to being shipped to our customers.
Shotting involves tipping the metal onto a refractory plate, causing it to form droplets. These then drop into a tank of water and solidify. The fresh water used in this process is cooled then recycled.
The resulting wet shot is collected by a screen.
The final product — coarse ferronickel — is graded by minimum and maximum grain size according to the customer’s requirements. At full capacity, the Metallurgical Plant will be able to produce 176,000 tonnes of this product each year, corresponding to 60,000 tonnes of nickel metal content.
The ferronickel shot is stored in silos and then packaged in two-tonne bags ready for loading into containers.
The deep-water port of Vavouto, a strategic element of Koniambo Nickel's infrastructure, can accommodate deep-draft vessels laden with materials and equipment on the way in and ferronickel on the way out. The cargo capacity of these vessels can go as high as 50,000 tonnes. The port is accessed via a channel that is 4 kilometres long, 140 metres wide and 12 metres deep. The 120-metre wharf is equipped with all the necessary installations (including a health control facility) for unloading incoming cargo and loading Koniambo Nickel's product.
From here, Koniambo Nickel's ferronickel is shipped to its customers in Asia, Europe and North America
Koniambo Nickel's industrial complex is in the North Province of New Caledonia, 310 kilometres from Nouméa.
Our hiring procedure
Koniambo Nickel's origins are enmeshed in New Caledonia's history. Its story began in 1966 with an announcement by General de Gaulle.
A high-quality nickel deposit, a genuine performance culture and a demanding sustainable development policy: Koniambo Nickel embodies a country's dream.
Koniambo Nickel SAS is a joint venture owned by Société Minière du Sud Pacifique (51%) and Glencore Xstrata (49%).