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Slurry Pipelines Conference 2015, Khouribga to Jorf Lasfar Pipeline , Slide 1

www.PatersonCooke.com

The Design and Engineering of the 187 km Khouribga to

Jorf Lasfar Phosphate Slurry Pipeline Alan Rosewall, Paterson & Cooke, Perth

Slurry Pipelines and Flow Equipment Conference 2015


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Introduction

Morocco now has one of the largest ore slurry pipeline

systems in the world The main delivery pipeline is 187 km long and transports

4400t/h of phosphate ore

The system has become an integral part of the OCP value

chain and their expansion plans


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Introduction

Client: OCP

Client representative: JESA

EPC Contractor: Tekfen Construction

Design engineers: Paterson & Cooke and Tekfen

Engineering


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Construction Statistics

50 000 tons of pipeline steel

1.7 million man days

At the peak of construction - 1800 people and 800

construction machines were employed

This paper provides a system overview and highlights some

of the challenges


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Location

Diameter Nominal Length

Daoui Feeder DN450 22 km

MEA Feeder – low grade DN400 1.8 km

MEA Feeder – high

grade

DN300 1.8 km

Halassa Feeder DN500 15 km

Ouled Fares Feeder

(future)

DN500 10 km

Mainline MEA to Jorf DN900 187 km

Total 227 km (10 km

future)


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System Description

• 14.9 km pipeline

• 1500 t/h• 2 trains of 5 pumps

each

• 1.8 km pipeline

• 700 & 1400 t/h

• Utilises thickener

underflow pumps

• 22.2 km pipeline

• 1400 t/h

• 2 trains of 4 pumps

each

• Variable choke

station

• 187 km

pipeline• 4400 t/h

• 2 trains of 6

pumps each

• Valve Station

• Pressure

Monitoring

Stations

• Variablechoke station

• 8 Storage

Tanks


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Feeder Pipelines – Daoui


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Feeder Pipelines – El Halassa


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Feeder Pipelines – MEA


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Feeder Pipelines


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Main Pipeline Route

Key Statistics

187 km long

Head station

elevation: 650m Maximum

elevation: 770m

Discharge

elevation: 100m Maximum slope:

12%


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Control of Main Pipeline

Control of the pipelinemust ensure

No slack f low on the

predominantly

downhill route profile

High enough velocityto avoid solids

deposition on pipe

invert

Turbulent rather than

laminar flow Flow rate and

pressure within the

design limits


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The system mustaccommodate a

wide range of

operating

conditions whilesatisfying the

design criteria

The figure shows

the relationshipbetween

volumetric and

solids throughput


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Trained operatorsguided by a visual

grade line display

of the system

They select flow

rate and chokingwithin limits

System

automatically

controls to flow rate

by adjusting speedsof pumps 1,2,5,6

and stopping or

starting pumps 3, 4.


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The valve stationis required to

divide static head

during shut-down.

Pressure

monitoringstations monitor

intermediate

conditions along

the pipeline.


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Instruments used for control and monitoring of the overlandpipeline:

• Tank level transmitter and level switches

• Pressure transmitters

• Flow meters

• Density meters

• BPL Analysers


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Batch Tracking:• Different grades of phosphate ore are mined, processed in

the wash plants and fed into storage tanks dedicated to

the pipeline.

• The control system tracks these batches and is able toautomatically control valves in order to directed these into

specific tanks.


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Equipment – Piping

Overland piping dimensional standard according to API 5L

Main line has API 5L X70 material

Feeders have API 5L Grade B material

Flanges are ASME B16.5 and B16.47 Series A with ASTM

A105 and ASTM A694 F70 material

Overland pipelines are internally lined with HDPE

Slurry station pipelines are lined with Polyurethane or

rubber

Water pipeline are internally lined with Epoxy


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The test loop is used to monitor

the pipeline hydraulic losses

before the slurry enters the

main pipeline. The

requirements made design and

manufacture a challenge:

• Matches the mainline ID

• Smooth joints despite being

made up of several

relatively tight radius bends

• HDPE liner sections were

custom made for eachspool and have a finely

grooved surface finish

creating smooth join


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High pressure PU-lined pipe spools for pump and

choke stations• Cast into straights, bends and tees using unique, removable patterns

• Special rubber lined steel gaskets with inward facing “ears” contain

the pressure while allowing a smooth transition between spools


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Equipment – Main Pumps

Six operating and six standby

1850 kW motors with air-cooledgearboxes

Separate, wear resistant volute

liners

Pressure limits of 6200 kPa

Variable speed drives give a

large head range from 10m to

50m for slurry and 80m on water

Separate gland seal water

plunger pump for each slurry

pump


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Equipment – Terminal Choke Station

Choke station designed for 10MPa

Four loops each with two ceramic orifice plates

Bursting

disk take-off

Fixed

chokes

Variable choke

bypass

Slurry feedline

Choke

loops


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The orifice plates are different sizes and by

combining various combinations, the control systemprovides a wide range of choking


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The effect of choking on the hydraulic grade line

High flow Low flow

Choke

head

Choke

head

Pumping

head

Pumping

head


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Equipment – Tanks

Each tank is 20m x 20m 250 kW agitators

Head Station: 4 tanks(2 groups of 2 tanks each)

Terminal Station: 8 tanks(3 groups of either 2 or 3

tanks each)


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Hydrostatic Testing

Pipeline must be pressure tested to 1.1 the design pressure

for not less than 4 hours (ASME B31.4) With multiple elevation changes, pipeline must be divided

into sections for testing

Plan was devised to

• Minimize number of test sections

• Allow filling from Oum er Rbia River

• Minimize water discharge

• Allow test and filling equipment to be removed after

testing


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Hydrostatic Testing

Test Planshowing testsections, transferpoints and testheads

Transfer point

between

sections 2 and 3


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Conclusion

The sheer size and complexity of the OCP Khouribga to Jorf

Lasfar phosphate slurry pipeline presented a number of uniqueengineering challenges, all of which were overcome. The

system has since been commissioned and it provides OCP

with a highly efficient transport system which is an essential

component of their value chain.

Pipeline

ROW

alanrosewall patersoncooke 151111032140 lva1 app6891

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