IBP1424_09

OVERVIEW OF THE LONG DISTANCE IRON ORE SLURRY PIPELINE FROM ANGLO FERROUS BRAZIL. Adarlan M. Silva1, Aline C. Passos 2, Daniel Santos3, Eduardo M. Orban4, Hélder D. Lisboa5, Nilton Gonçalves6, Robson C. Guimarães7

Copyright 2009, Brazilian Petroleum, Gas and Biofuels Institute - IBP This Technical Paper was prepared for presentation at the Rio Pipeline Conference and Exposition 2009, held between September, 22-24, 2009, in Rio de Janeiro. This Technical Paper was selected for presentation by the Technical Committee of the event according to the information contained in the abstract submitted by the author(s). The contents of the Technical Paper, as presented, were not reviewed by IBP. The organizers are not supposed to translate or correct the submitted papers. The material as it is presented, does not necessarily represent Brazilian Petroleum, Gas and Biofuels Institute’ opinion, or that of its Members or Representatives. Authors consent to the publication of this Technical Paper in the Rio Pipeline Conference Proceedings. Resumo O objetivo deste trabalho é apresentar uma visão geral do mineroduto de minério de ferro da Anglo Ferrous Brazil. Anglo Ferrous Brazil é um empresa do Grupo Anglo American plc que é um dos maiores grupos de mineração e recursos naturais do mundo. Minas-Rio é um projeto de minério de ferro, de classe mundial, que está sendo desenvolvido no Brasil para produzir 26.6 milhões de toneladas de concentrado por ano. A Mina, Planta de Beneficiamento e Estação de Bombas 1 estarão localizadas em Conceição do Mato Dentro, Minas Gerais e a Estação Terminal estará localizada no Porto do Açú em São João da Barra, Rio de Janeiro. O mineroduto será um dos maiores diferenciais do Projeto Minas-Rio e sua vida útil está estimada em 20 anos. O mineroduto terá 525 quilômetros de extensão e será construído com tubulações de 26 polegadas, diâmetro externo, utilizando aço API 5L X70. Do quilômetro 314 ao 480, será instalado uma tubulação de 24 polegadas, para prevenir a formação de vácuo, após a Estação de Bombas 2. A Estação de Bombas 1 irá operar com 8 bombas de deslocamento positivo e foi projetada para fornecer energia hidráulica necessária para transportar o concentrado de minério de ferro até a Estação de Bombas 2. A Estação de Bombas 2, localizada no quilômetro 240, foi projetada para operar com 10 bombas. A Estação de Válvulas será localizada no quilômetro 347 e será utilizada para quebrar a carga estática entre a Estação de Bombas 2 e a Estação Terminal, durante uma parada do mineroduto. Um sistema de proteção catódica será instalado para evitar a corrosão externa e 10 Estações de Monitoramento de Pressão irão monitorar as condições hidráulicas do bombeamento. Existe também um cabo de fibra ótica para comunicação entre a Estação de Bombas e Estação Terminal. O mineroduto será construído por tubulações com diferentes espessuras, dependendo da pressão requerida na região. A velocidade de transporte poderá variar entre 1.5 m/s a 1.8 m/s com vazão nominal entre 1826 m³/h e 2105 m³/h.

Abstract The objective of this paper is to present an overview of the long distance iron ore slurry pipeline from Anglo Ferrous Brazil. Anglo Ferrous Brazil is a company of Anglo American plc that is one of the world’s largest mining and natural resource company. Minas-Rio is a world class iron ore project which has been developed in Brazil aiming to produce 26.6 million tons per year of concentrate. The mine, concentrator and pump station 1 will be located in Conceição do Mato Dentro, Minas Gerais state, and the terminal station will be located at Açú Port in São João da Barra, Rio de Janeiro state. The long distance iron ore slurry pipeline will be one of major differentials of Minas-Rio Project and its useful life was initially estimated in 20 years. The slurry pipeline has a total length of 525 kilometers and will be constructed from predominately 26 inches external diameter API 5L X70 pipes. From kilometer 314 to kilometer 480, 24 inches pipe will be installed to prevent slack flow downstream pump station 2. The pump station 1 is designed to provide the hydraulic head necessary to transport the concentrate iron ore slurry with 8 positive displacement pumps to pump station 2. The pump station 2, located 240 kilometers downstream pump station 1, is designed to operate with 10 positive displacement pumps. The valve station will be located at kilometer 347 and will be used to break the static head between pump station 2 and the terminal station during a slurry pipeline shutdown.

______1 Adarlan M. Silva, MSc, Coordinator, Operations – Anglo Ferrous Brazil 2 Aline C. Passos, Eng., Maintenance Planning Control, Maintenance - Anglo Ferrous Brazil 3 Daniel Santos, Eng., General Manager, Operations & Maintenance - Anglo Ferrous Brazil 4 Eduardo M. Orban, Eng., Manager, Operations & Maintenance – Anglo Ferrous Brazil 5 Hélder D. Lisboa, Eng., Electric Engineer, Maintenance - Anglo Ferrous Brazil 6 Nilton Gonçalves, Eng., Mechanic Engineer, Maintenance - Anglo Ferrous Brazil 7 Robson C. Guimarães, Eng., Mechanic Engineer, Maintenance - Anglo Ferrous Brazil Rio Pipeline Conference & Exposition 2009

A cathodic protection system will be installed to mitigate external corrosion and 10 pressure monitoring stations to controlling hydraulic conditions, there is also a fiber optic cable interconnection between pump station 1 and terminal station. The pipeline will be constructed with several wall thicknesses, dependant upon the pressure requirements at the location. The transportation velocity ranges from 1.5 m/s to 1.8 m/s, with a flow rate between 1,826 m³/h and 2,105 m³/h.

1. Introduction

1.1 Business Overview

Anglo American plc has an unique portfolio of high quality mining assets and natural resources includes precious, base metals and bulk commodities. Anglo operates in Africa, Europe, South and North America, Australia and Asia.

Anglo American plc has five business units: Platinum, Diamonds, Base Metals, Ferrous & Industries, and Coal. The iron ore is a integrated part of the Ferrous Metal Business Unit that is on development in Anglo.

Ferrous & Industries has iron ore, steel, aluminium and manganese operations on four continents – South Africa, North and South America, and Australia. It is primarily focused on developing Anglo position in the global iron ore market through a 63.4% shareholding in Kumba Iron Ore in South Africa, the Minas-Rio project and a 70% stake in the Amapá mine in Brazil, acquired in August 2008. Kumba currently operates two mines in South Africa – Sishen in the Northern Cape, and Thabazimbi, in Limpopo.

1.2 Anglo Ferrous Brazil Overview

Anglo Ferrous Brazil is a company of Anglo American plc that is one of the world’s largest mining and natural resource company. Anglo Ferrous Brazil currently owns 70% of the Amapa project, Minas-Rio iron ore project and 49% stake in LLX Minas-Rio.

The Amapa iron ore project is located in Amapa state in the North of Brazil. The construction of Amapa project was completed in 2007, with initial production in December 2007 and with annual capacity of 6.5 million tons per year of iron ore. Anglo Ferrous Brazil currently owns 70% of the Amapa project and Cleveland Cliffs Inc. owns 30%.

Minas-Rio iron ore project is located in Minas Gerais and Rio de Janeiro states in Brazil. The project is due to begin production in 2012 with potential production of 26.6 million tones per year of concentrate.

1.3 Minas-Rio Project Overview

Minas Rio project is an integrated system which includes an open pit mine, beneficiation plant, tailings disposal, slurry pipeline, filtering plant and port.

The iron ore mine, beneficiation plant and pump station 1 is located in Conceição do Mato Dentro region, 150 kilometers far from the city of Belo Horizonte, in the North of Minas Gerais state, Brazil. The beneficiation plant is connected to the Açú Port, in North of Rio de Janeiro State, by a slurry pipeline.

The Minas Rio concentrator was designed to process on average 6,496 metric tons of ore per hour (143,432 tons per day) at a projected plant availability of 95.0%. The plant will process 56.9 million tons of ore per annum with potential production of 26.6 million tones per year of concentrate.

The Anglo Ferrous Brazil iron ore consists mainly of quartz and hematite particles with 39.8% of iron and 40.0% of silica that will feed the beneficiation plant: crushing, screening, roller press, primary grinding circuit assures sufficient reduction and liberation of the iron ore particles. It will be then deslimed, with the ultrafine material being removed in cluster cyclones before flotation circuit where waste material such as silica will be separated from the iron particles. The ore finally will be reground and feed a concentrate thickener. The concentrate with 68 percent of solids is pumping for slurry pipeline transport to Açú Port. Approximately 80% of the iron will be recovered during the concentration. The iron ore content in the concentrate is average 68.0% and the silica content is 1.1% average.

An overview of the plant process is shown in Figure 1.

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Figure 1. Minas-Rio Process flow sheet

1.3.1 Key Informantions

 Product: Iron ore  Location: Conceição do Mato Dentro, Minas Gerais – São João da Barra, Rio de Janeiro, Brazil  Mineral Type: Low-grade itabiritic ore, hematite and magnetite  Mining Method: Open pit  Processing Method: Integrated system: mine, beneficiation, slurry transport, filtering and shipment  Annual Production: 26.6 million tones of concentrate  Metallurgic recovery: 85%;  Mass recovery: 45%  Concentrate: 26.6 million tons per year – wet base  Roller presses are used to enhance the reduction index - The largest roller press in the world (Crushing step)  Operational Energy consumption: 5,7 kWh/t;  The trade off between vertimill against ball mill present an energy saving of 37%  The longest iron ore slurry pipeline in the world (525km)  The largest Ceramic Disc Filters in the world (144m²)

2. Pipeline Overview

The Anglo Ferrous Brazil iron ore slurry pipeline has a total length of 525 kilometers and is constructed from predominately 26 inches outside diameter API 5L X70 unlined steel pipe. From kilometer 314 to kilometer 480, instead of 26 inches, 24 inches pipe will be installed to prevent slack flow downstream of pump station 2 of the pipeline.

The route was based on the shortest distance line connecting the beneficiation plant to the terminal station. The maximum slope allowed is 15%. 3 Rio Pipeline Conference & Exposition 2009

The pipeline system is designed to transport 26.6 million tones per year of iron ore concentrate for 20 years operation, running 365 days a year, 24 hours a day with 95% overall efficiency.

The pipeline is designed to transport iron ore slurry for the conditions shown in Table 1.

Table 1 – Operating Condition

Production Production % solids Flow rate Continuous Operating (million tons per (tons per hour (by (m3 / h) Condition year – dry base) - dry base) weight) Minimum 19.8 2,382 64 1,826 Expected Normal 24.5 2,944 68 1,986 Design 26.0 3,121 68 2,105

Pipeline over pressure protection will be achieved by the following installed devices:

 Relief valves installed on the discharge of all mainline pumps at pump station 1 and pump station 2.  A rupture disc installed at the entrance to sump station 2.  A divert valve to the remix tank at pump station 2 that will open automatically at the high pressure set-point.  A by-pass rupture disc line installed at the entrance to valve station.  A rupture disc installed at the terminal station entrance.  10 strategically located pressure monitoring stations installed over the length of the pipeline.

2.1 PUMP STATION 1

Pump station 1 is located in Conceição do Mato Dentro, Minas Gerais state. The station is designed to provide the hydraulic head necessary to transport the concentrate slurry to pump station 2, located 240 kilometers downstream.

At pump station 1 there are four agitated slurry storage tanks, 21.5 m diameter x 17 m high. The tanks are sized such that the combined working capacity allows either the beneficiation plant or the pipeline to conduct a planned shutdown, with 2 tanks full and 2 tanks empty, without the beneficiation operating facility being affected.

8 GEHO pumps, TZPM 2000, the largest piston diaphragm pumps, (7 operating, 1 standby) will be installed at the pump station 1. To prevent damage to the equipment, the pumps are equipped with three levels of over pressure protection. Each pump has a rated capacity of 300 m3/h and 18.28 MPa discharge pressure. For the expected normal operating condition, seven pumps operate at 95% speed leaving one pump on standby. To achieve the minimum pipeline flow, six pumps are required to operate, however 100% capacity from each pump are required.

A test loop is provided that may be used independently of normal pipeline operations, or alternately slurry may be pumped through the loop and then directed to the suction header of the mainline pumps. The test loop is used on an as- needed basis to investigate the characteristics of the slurry during startup and when laboratory results indicate a change in slurry properties. Slurry that is outside of the design specifications should not be committed to the pipeline until test loop results prove that the material can be safely transported.

A pig launcher is permanently installed in the station discharge piping. The pipeline not need to shutdown to launch a pig.

2.2 PUMP STATION 2

Pump station 2 is designed to provide the hydraulic head to transport the slurry to the terminal station and strategically is located at kilometer 240 so that the maximum output from pump station 1 is achieved.

The station is designed to be operated in automatic mode from the control room at pump station 1 but may be operated in local or automatic from pump station 2 with the permission of the pump station 1. At the entrance to the station, a choke station is installed. 8 vertical loops containing 2 ceramic orifices each control slack flow conditions in the upstream section of the pipeline.

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10 GEHO pumps, TZPM 2000 are installed at the pump station 2. For normal operations, 8 pumps operate and 2 pumps are in standby. Each pump has a rated capacity of 263 m3/h and 20.62 MPa discharge pressure.

An emergency pond with a capacity of 242,000 m3 has been provided at pump station 2. The pond will store sufficient water for flushing the entire downstream section of the pipeline to the terminal station. It also has sufficient capacity to accept the entire volume (water or slurry) contained in the upstream pipeline section from pump station 1.

A pig receiver and pig launcher is permanently installed in the station piping. The pipeline shall remain in operation during the receiving and launching operations.

2.3 VALVE / CHOCK STATION

Valve station is used to break the static head between pump station 2 and the terminal station during a pipeline shutdown. A wear valve and seal valve will be operated to isolate the upstream and downstream sections of the pipeline.

The two isolation valves are included in the pipeline automatic shutdown sequence. The station is designed to be operated in automatic mode from the control room at pump station 1, but may be operated in local with the permission of the pump station 1 operator.

Valve station is located at kilometer 347 and during water batches 8 vertical loops containing 2 ceramic orifices each will control slack flow conditions in the upstream section of the pipeline. Each orifice has been sized to dissipate 50 meters of head.

By varying the number of choke loops in operation, back pressure in the pipeline can be controlled and slack flow avoided. The choke station will be only utilized when water batches are being pumped and can be isolated, when not required, or for maintenance.

A pig receiver and pig launcher is permanently installed in the station piping. The pipeline shall remain in operation during the receiving and launching operations.

2.4 TERMINAL STATION

At the end of the pipeline in Açú Port, São João da Barra city, Rio de Janeiro state, the slurry will be normally directed to a concentrate thickener. The terminal storage tanks are sized such that the pipeline can continue operating for 10 hours while the filter plant operates at 50% throughput.

An alternative route for slurry arriving at the terminal is direct to the storage tanks. The ceramic disc filters are designed for a slurry concentration of 71% of solids. If slurry is delivered directly to the storage tanks at a normal concentration of 68% of solids then filtering throughput, as a result of the lower concentration slurry is reduced by 25%. Direct feed from the pipeline to the storage tanks will only be done if the concentrate thickener is offline.

A pig receiver is permanently installed in the station entrance piping. The pipeline shall remain in operation during the pig receiving operation.

2.5 SUPERVISORY CONTROL AND DATA ACQUISITION (SCADA) SYSTEM

Two SCADA workstations are provided in pump station 1 control room to permit access to pipeline operating screens and data. Two password-protected operator workstations are provided at pump station 2. The password protection only disables the command feature. The pump station 2 operator can view real time pipeline information at all times.

During normal operation the pipeline is controlled from pump station 1; however, in emergency situations, the pipeline can be operated from pump station 2 or the terminal station under voice supervision from the pump station 1 operator. Under this situation, the affected station will be operated in local mode.

A password-protected workstation is provided at the terminal station as a second back-up to operate the pipeline. At valve station, a SCADA workstation is provided solely for monitoring the pipeline operation. It is essential that the

5 Rio Pipeline Conference & Exposition 2009 pipeline is only operated from one location at any one time. If workstations are left unlocked at other locations, then someone may accidentally cause a serious pipeline “event”. 2.6 SLACK FLOW AND PRESSURE MONITORING STATIONS

There are 10 pressure monitoring stations strategically located between pump station 1 and the terminal station.

The pressure monitoring stations are also monitor intermediate conditions in the pipeline. This pressure data assists in batch tracking and provides information that supports operator decision-making. Additionally, the pressure monitoring station data provides the necessary input into the pipeline leak detection system found in the Pipeline AdvisorTM.

2.7 TELECOMMUNICATION

A Fiber optic system serves as primary voice communication along the pipeline and for data collection/ transmission. All communication equipments are supplied with an uninterruptible power supply system to allow continued operation during power outages.

2.8 CATHODIC PROTECTION SYSTEM

An impressed current cathodic protection system is installed to protect the pipeline from external corrosion. Rectifier stations and anode beds are installed at strategic locations.

Potential (voltage) measurements shall be made at all test locations in both the current on and current off status.

3. CONTROL PHILOSOPHY

The Anglo Ferrous Brazil pipeline is designed to continuously operate at a throughput range of 2,382 to 3,141 dry metric tons per hour of iron concentrate. A minimum continuous slurry production rate of 2,382 tph at 64% solids is required for the pipeline; otherwise batch water is required.

The transportation velocity ranges from 1.60 m/s to 1.86 m/s, with a flow rate between 1,826 m³/h and 2,105 m³/h. Minimum flow rate of 1,826 m3/h at the pipeline must be controlled to avoid settling problems and plug formation.

The figure 2 shows operating range of the Anglo Ferrous Brazil pipeline.

Anglo Ferrous Brazil - 24.5 MTA - 26/24 - inches 95% Availability

30

29 Operate Point, 24.5 MTA Maximum limit with 70 % 6% SF 18.28 MPa (2,651psi) 28

27 68 %

26 66 % 25

24 64 %

23

22

Produção (MTPA) Produção 21

20

19 Water Batching 18 operation Min.operating Max flow rate 17 velocity 1.6 m/s = 1826 m3/h velocity 1.86 m/s = 2105 m3/h 16

15 1750 1800 1850 1900 1950 2000 2050 2100 2150 2200 Vazão (m3/h)

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Figure 2. Operating Range In general, the intent of the control philosophy is to fully automate as many sequences as possible. All automated operations have a hold mode to allow operators to confirm execution of each step in the automatic sequence, prior to initiation.

The pipeline flow rate provides the primary level for the pipeline control philosophy. Operating pressure data at all pump stations, pressure monitoring stations and at the pipeline terminal, provide the secondary level of control. During water batching, it is expected that pump station 1 and pump station 2 discharge pressures will be controlled to prevent over pressure conditions. The pipeline flow rate is controlled to keep maximum pumping pressures below set limits.

The figure 3 shows the profile and hydraulic line of the Anglo Ferrous Brazil pipeline.

Figure 3. Profile and hydraulic grade line

3.1 PROCESS CONTROL

Process Control refers to the control of process variables with the use of a controller to achieve a desired operation. This includes slurry density control from 64% to 70% (by weight) and pipeline flow rate control from 1,826 to 2,105 m3/h, based on accumulative pump speed. Suction pressure control is based on accumulative, or individual, pump speed.

Mainline pumps speed at pump station 1 are controlled by the flow-rate set-point or pump stroke count; however, suction or discharge pressure shall take over if a low suction or high discharge set-point will be reached. The action of the pressure control loops is to slow down the mainline pumps speed to prevent reaching a shutdown set-point. In automatic mode, the speed control loop outputs are the same for all pumps.

At pump station 2 the pump speed is controlled by the suction pressure set-point; however, discharge pressure shall take over if the high discharge pressure set-point will be reached.

3.1.1 DENSITY CONTROL

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The slurry density is measured in the discharge piping of the charge pumps. The operator controls the slurry density of feed to the mainline pumps by adjusting the controller set-point to a desired value. The density set-point is selected based on slurry properties (lab tests), and to keep the slurry density within the pipeline operating range.

If the density is marginally lower than the minimum 64% solids (by weight), an alarm is displayed. If the solids correction can not be achieved quickly, the pipeline should switch to water until the problem is rectified, or change to another storage tank. The slurry in the tank should be kept for blending with higher concentration material. If the density is higher than 70% solids, or the selected set-point, the dilution water system injects water automatically to adjust the density.

3.1.2 PIPELINE FLOW RATE CONTROL

Prior to pumping operations, the pipeline operator determines the concentration of the slurry and checks the limits of operation (minimum operating velocity and maximum discharge pressure). The pumping flow rate is then determined which is used as a set-point for maintaining a pre-set flow operation. The flow rate should generally be maintained as close to the production rate from the beneficiation plant as possible.

3.1.3 pH CONTROL

A caustic ash system is designed to regulate the slurry pH in 10.5. The pH is monitored at the slurry storage tanks. The operator controls the pH of slurry to minimize or avoid internal corrosion of the pipe.

Some alternative reagents are been tested as alternatives to replace the lime for rheology control of the iron ore slurry during the pumping. The results of the tests with organic coagulants showed that a small dosage affected the slurry rheological behavior, as well as the water clarification after settling, in the same manner as lime, with therefore they can replace it as transport reagents at this condition.

New tests have been development to evaluate the effect of the coagulant/caustic dosage with the internal corrosion of the pipe.

4. REFERENCES

ANGLO FERROUS BRAZIL – Operating and Control Philosophy, PSI do Brasil, 52 pages, 2008.

ANGLO FERROUS BRAZIL – Laboratory Report, Anglo Ferrous Brazil, 26 pages, 2008.

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