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Demand side management of a run-of-mine ore milling circuit
Dissertation (MEng)--University of Pretoria, 2015.
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| Format: | Thesis |
| Language: | en_US |
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University of Pretoria
2015
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| _version_ | 1867613605394907136 |
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| access_status_str | Open Access |
| author2 | Craig, Ian K. |
| author_browse | Craig, Ian K. |
| author_facet | Craig, Ian K. |
| collection | Thesis |
| dc_rights_str_mv | © 2014 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MEng)--University of Pretoria, 2015. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/44020 |
| institution | University of Pretoria (South Africa) |
| language | en_US |
| last_indexed | 2026-06-10T12:38:48.199Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2015 |
| publishDateRange | 2015 |
| publishDateSort | 2015 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/44020 Demand side management of a run-of-mine ore milling circuit Craig, Ian K. Matthews, Bjorn Load shifting Demand side management Model predictive control Real-time optimizer Milling circuit Run-of-mine ore Time-of-use tariff UCTD Dissertation (MEng)--University of Pretoria, 2015. In South Africa, where 75% of the worlds platinum is produced, electricity tariffs have increased significantly over recent years. This introduces challenges to the energy intensive mineral processing industry. Within the mineral processing chain, run-of-mine ore milling circuits are the most energy-intensive unit processes. Opportunities to reduce the operating costs associated with power consumption through process control are explored in this work. In order to reduce operating costs, demand side management was implemented on a milling circuit using load shifting. Time-of-use tariffs were exploited by shifting power consumption of the milling circuit from more expensive to cheaper tariff periods in order to reduce overall costs associated with electricity consumption. Reduced throughput during high tariff periods was recovered during low tariff periods in order to maintain milling circuit throughput over a week long horizon. In order to implement and evaluate demand side management through process control, a load shifting controller was developed for the non-linear Hulbert model. Implementation of the load shifting controller was achieved through a multi-layered control approach. A regulatory linear MPC controller was developed to address technical control requirements such as milling circuit stability. A supervisory real-time optimizer was developed to meet economic control requirements such as reducing electricity costs while maintaining throughput. Scenarios, designed to evaluate the sensitivities of the load shifting controller, showed interesting results. Mill power set-point optimization was found to be proportionally related to the mineral price. Set-points were not sensitive to absolute electricity costs but rather to the relationships between peak, standard, and off-peak electricity costs. The load shifting controller was most effective at controlling the milling circuit where weekly throughput was between approximately 90% and 100% of the maximum throughput capacity. From an economic point of view, it is shown that for milling circuits that are not throughput constrained, load shifting can reduce operating costs associated with electricity consumption. Simulations performed indicate that realizable cost savings are between R16.51 and R20.78 per gram of unrefined platinum processed by the milling circuit. This amounts to a potential annual cost saving of up to R1.89 m for a milling circuit that processes 90 t/h at a head grade of 3 g/t. Electrical, Electronic and Computer Engineering Unrestricted 2015-03-16T13:02:43Z 2015-03-16T13:02:43Z 2015-04-23 2015 Dissertation Matthews, B 2015, Demand side management of a run-of-mine ore milling circuit, MEng dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/44020> A2015 http://hdl.handle.net/2263/44020 en_US © 2014 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | Load shifting Demand side management Model predictive control Real-time optimizer Milling circuit Run-of-mine ore Time-of-use tariff UCTD Demand side management of a run-of-mine ore milling circuit |
| title | Demand side management of a run-of-mine ore milling circuit |
| title_full | Demand side management of a run-of-mine ore milling circuit |
| title_fullStr | Demand side management of a run-of-mine ore milling circuit |
| title_full_unstemmed | Demand side management of a run-of-mine ore milling circuit |
| title_short | Demand side management of a run-of-mine ore milling circuit |
| title_sort | demand side management of a run of mine ore milling circuit |
| topic | Load shifting Demand side management Model predictive control Real-time optimizer Milling circuit Run-of-mine ore Time-of-use tariff UCTD |
| url | http://hdl.handle.net/2263/44020 |