MediaWiki API result

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            "70": {
                "pageid": 70,
                "ns": 0,
                "title": "Size does matter",
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                        "*": "==Sample dimensions==\nPower models generally operate with a series of calculations at different size classes.  Each size class typically has a specific test that returns the characteristic hardness of that class. \n\n===Breakage mechanisms by size classes===\nThe mechanism of breakage tends to change as the size of a rock changes.  In general:\n* Breakage in coarse rocks is dominated by impact (crushing) action.\n* Breakage in the medium (intermediate) size class is dominated by attrition (compression and breaking angular chunks of rock).\n* Breakage in the fine size class is dominated by abrasion (rubbing of particles against other particles).\n\n===Modelling of breakage===\nWhich tests correspond to which size classes varies by the type of model used, but these can be generalized into the follow categories based on the dimensions of the samples tested:\n\n{{Tests by size class}}\n\n===Extrapolating across size classes===\nOrebodies tend to have relationships between the different size class breakage types, and once enough data has been collected, is is possible to project breakage across size classes.\n\nThe family of Bond tests have different apparatus for different size classes.  The observed behaviour of copper porphyries is that no relationship exists between the coarse Bond crushing work index (WiC) and the medium-sized bond rod mill work index (WiRM).  This is interpreted as being due to fractures that exist in the rock with a typical spacing of 50 mm -- the crushing test acts to open these existing fractures (which requires little energy), but the rod mill work index must act on the matrix of the rock (which requires more energy) since all the fractures have now be broken open.  This observed behaviour is rarely due to rock resisting the different breakage mechanisms (impact and attrition, respectively) in unusual ways.\n\nThe method of the SMC test will not pick up this nuance of copper porphyries because the same is already crushed to remove all the coarse fractures (the SMC test typically sees material -33 mm nominal dimension).  The Mic value reported in the SMC test is extrapolated from the observed matrix breakage and will over-estimate the amount of energy required to break the fractures that exist in many porphyries at coarse sizes.\n\n<gallery>\nFile:Size_WiC_v_WiRM.png|Bond work index values at coarse and medium size classes\nFile:Size_Mic_v_Mia.png|SMC Mi extrapolating coarse value from medium size classes \n</gallery>\n\nModels that do not have a coarse test, such as Morrell Mi and Amelunxen SGI, will generally extrapolate grindability results from a medium size class using the model practitioner's database -- the SMC test extrapolation can be seen in the red figure, above.  These extrapolations are valid for the ore types represented in the database, but should be used with caution for orebodies that have unknown characteristics or where the orebody does not match the type that dominates the practitioner's database.\n\n===Comments on size classes===\n* The CEET2 model is a hybrid population-balance and power model.  The '''CI''' measurement is not used directly in the power modelling; it is used to predict the particle size distribution (F<sub>80</sub> and F<sub>50</sub>) sizes of the SAG mill feed.  The net effect of adjusting the particle size distribution is similar to what is observed in the Bond/Barratt model by adjusting the crushing work index which dictates the hardness of the coarse size class.\n* The '''CI''' measurement is conducted on particles similar to the 'medium' size class in the Bond/Barratt model, but published information <sup>[[Bibliography: Testwork programs|Doll &amp; Barratt, 2011]]</sup> suggests that it is a reasonable proxy for the crushing properties typically measured in coarser particles.  The '''CI''' test is particularly useful as it can be conducted on much smaller core sizes than the Bond crushing work index, making it particularly suitable for pre-feasibility programs with limited availability of whole-diameter HQ or PQ size samples.\n* The Bond/Barratt model uses a series of hidden 'calibration transfer sizes' to determine the overall grindability of a sample.  These transfer sizes control the degree of weighting that each of the tests has on the overall grindability result.  In general, the default size classes in the model match the transfer sizes observed in the laboratory tests; but these can be adjusted by the engineer (setting the min/max T<sub>80</sub> limits) if there are other 'natural' transfer sizes observed in the rock (example: a porphyritic rock type with 1.5\u20132.5 mm clasts can reasonably be expected to produce a 1.5\u20132.5 mm T<sub>80</sub> range).\n* The JK DWT and SAGDesign tests blend results of several size classes together to predict a composite grindability prediction.  Composite samples are a valid approach that avoids the need to set 'transfer sizes', but do require correctly constructed 'feed composites' containing the correct proportions of the size fractions.  Laboratory bench-scale testing is limited in the top size that can realistically be tested, and care is required to correctly represent the proportion of this coarse fraction in a composite.\n** The JK DWT performs a mathematical compositing of the results of several different size classes to predict model parameters '''A''' and '''b'''.\n** The SAGDesign test mixes a feed charge to a small SAG mill consisting of several different size classes.  The exact behaviour of each size class is not determined; only the composite grindability of the mixture is determined.\n** Pilot plant samples are an extreme variant of this type of test that uses composites.  Pilot plants can both handle coarser feed (up to 150 mm) and can create circulating loads of 'pebbles' (critical size) that can not be observed in laboratory bench-scale tests."
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            "150": {
                "pageid": 150,
                "ns": 0,
                "title": "Software change log",
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                        "*": "==Change Log==\n\n=== 2024-04-13: Text changes describing power === \n* Tweaked the text to synchronize the way power is described between the flowsheet, tent diagrams, and mill details.\n* \"Usable\" label has been replaced with either \"drawn\" or \"available\"\n\n=== 2023-08-03: Monte Carlo simulation model, Bond/Barratt Single-Stage SAG models === \n* Monte Carlo now available for Bond single-stage SAG model, see [[:Category:Monte_Carlo]].\n\n=== 2023-06-08: Monte Carlo simulation model, Bond/Barratt SABC/SAB models === \n* New capability to run Monte Carlo models, see [[:Category:Monte_Carlo]].\n\n=== 2023-02-12: New feature, filenames of downloadable report & spreasheet  ===\n* The downloadable documents related to running a model now have much more useful filenames, including the date that the document was generated and for which project.\n\n=== 2023-01-31: Bugfix, administrators now see all projects ===\n* Fixed a bug where people with Admin level access could not see projects in their client area unless the Admin who actually created the project manually adds the other admins to the access control list.  Only people with User level access should be unable to view projects unless explicitly granted access.\n\n=== 2022-06-10: Mih model fix for no result table ===\n* Fixed a bug where the Morrell Mi models for HPGR circuits were failing to provide a table of model outputs (for all samples).  \n\n=== 2022-05-26: SABC Mi models use peb cr CSS for Epeb ===\n* The Morrell Mi models for SABC circuits now read the CSS the user has set for the pebble crusher to compute Epeb.  Before a fixed CSS of 12,500 \u00b5m was used.\n\n=== 2022-03-28: added VaryP80 and VarySpeed functionality to Mi BM models ===\n* The Morrell Mi models for tertiary crushing & single stage ball milling and HPGR & ball milling down have the same functionality as the SAG models where a maximum circuit throughput can be specified and the mills will either overgrind or vary the BM speed to compensate.\n\n=== 2022-01-01: Minor back-end SQL change ===\n* Minor change in the SQL code that generates a list of model results.  The latest MariaDB added a new reserved word \"offset\" that was used as a local column in a subquery; this was failing on the backup server (but never affected the main server).\n\n=== 2021-09-20: Changed operation of SSBM contingency ===\n* SSBM contingency now operates in the same way as CFsag and CFball, where Etotal now equals (Essbm\u00d7contingency).  So 1.0 is Etotal=Essbm, and 1.1 is Etotal=1.1\u00d7Essbm.  Old behaviour had a hidden +1, so old behaviour was Etotal=Essbm\u00d7(1+contingency).\n\n=== 2021-03-26: Added Josefin equation to Morrell SSBM model ===\n* Mib is now computed using a Hukki exponent if one is entered in the circuit configuration.  Users should note that the Hukki exponent for Mi models has a different value to Hukki exponents for Bond models.\n\n=== 2020-12-23: Bug fixes, laboratory listing ===\n* Fixed a bug where laboratory data entry would crash without meaningful feedback if a 'short name' is invalid.  Added error msgs for 'duplicate' and 'too long' conditions when creating or modifying a laboratory record.\n\n=== 2020-10-05: Added ball wear estimate to ball mills ===\n* Added an Improved Benevente equation to the ball mill summary pages.  Requires the sample have a Bond Ai (abrasion index) value in order to display.  This value is not picked up in the report tables, so you need to look at the ball mill summary pop-up on each simulation to find this value.  A future update will include this estimate on the report output tables.\n\n=== 2020-05-15:  Changed units of Levin B  ===\n* Switched the output units of Levin B to mWh/rev (was kWh/rev previously, which made unusably small numbers)\n\n=== 2020-05-08:  Bugfix for testwork program names  ===\n* Fixed a bug preventing the renaming of an existing testwork program\n\n=== 2020-04-08:  Added new Nordberg ball mill model for dry grate discharge ===\n* Mill power draw model for dry grinding.  Add an Essbm contingency of 1.30 when using a Bond-Rowland model (this is for the EF1 factor, 1.3 for dry grinding)\n\n=== 2020-03-23:  Tent diagram, sample density(SG) ===\n* Fixed current sample density not passing through to tent diagram when manual entry field is empty.\n\n=== 2020-03-21:  Server upgrade, SSSAG refactoring ===\n* Server operating system and Debian base packages updated.  \n* Single-stage SAG mill models changed, removed open circuit SAG and replaced with two closed circuit SAG options, one with other without pebble crushing.\n* Mill model detail pages now include an extra line of model detail showing values for key model sub-components.\n\n=== 2020-02-20: Crusher and WiBM table refactoring ===\n* Refactored the crusher class into two distinct classes, one for cone crusher and other for HPGR.\n* Refactored the ball mill work index testwork database table to include percentage of test feed passing the closing size.\n* Added calculation of the Levin-B value to Wi<sub>BM</sub> detail calculation.\n\n=== 2019-12-05:  SSBM Mi model ===\n* Added Morrell Mi model for secondary, tertiary cone crushers and single stage ball milling \n* changed icon on manual override submit buttons on circuit flowsheet panel.\n* Fixed Morrell Mi models not honouring manually entered F80 and P80 overrides\n\n=== 2019-05-03: Tent diagram caption ===\n* Fixed a bug in the density displayed in the caption of a tent diagram.\n\n=== 2019-02-20: Raw Bond Model ===\n* Fixed a bug in the transfer size computation.\n\n=== 2018-06-26: Upgraded Mpdf library ===\n* June 2018 server upgrade broke the ability to create PDF reports.  The Mpdf library was upgraded to the latest version minor code tweaks were done to connect it into the code base.\n\n=== 2018-05-30: Circuit t/h limits, sample density ===\n* Circuit t/h limits are now enforced when running models, and the model predicts one possible outcome where mill charges and speeds change to accommodate a reduced throughput (there are infinitely many mathematically valid possibilities).\n* Determination of the sample density in the situation where there is no WiC density and multiple DWT densities has changed.  Old behaviour is to pick the last DWT test density, new behaviour is to arithmetically average all DWT densities for the sample.\n\n=== 2018-04-15: Austin SAG model default cone angle, E_SSBM for SGI & Mi models  ===\n* Calculations involving the Austin SAG model were not using the default 15 degree cone angle, defaulting to zero (flat-ended mill).  Fixed so that no cone angle entry now is interpreted as 15 degrees.\n* SSBM calculation corrected for SGI and Mi models (EF4 value now uses Bond methodology)\n\n=== 2017-09-10: Feed and product (F80, P80) sizes manually adjustable, El Soldado SGI model ===\n* Temporary changes to the F80 and P80 sizes can now be entered on the flowsheet display page (just as you can manually adjust test results on a flowsheet page).  These changes are not saved, but allow users to see the effect of F80 & P80 changes without changing the stored circuit settings.\n* The Single Stage SAG mill model using SGI values has been changed to the El Soldado basis (Becerra and Jorquera, Procemin 2016).\n\n=== 2017-09-05: Minor cleanup, Mih model ===\n* Forced the Mih model (Morrell HPGR model) to check that Sc is not greater than 1.  This requirement is explained in the GMSG Morrell standard (2015-08-21).\n* Discontinued the 'particle size plotting' tool.  Modern browsers won't run java applets anymore, so the tool won't function. :'(\n\n=== 2017-08-15: SSL certificates changed ===\n* Switched the main site SSL certificate to LetsEncrypt.  Added certificate to the wiki.\n\n=== 2017-03-21: Bond models can configure internal transfer sizes ===\n* The various Bond models now have the ability to modify the calibration internal transfer sizes.  Rare that you would want to do this, but Alex encountered a project that needed this capability.\n* Tent diagrams can now have non-integer ball charges and filling volumes.\n\n=== 2017-03-11: Changed Mia, Mic estimate from A\u00d7b for SMC model ===\n* Updated the prediction of Mia and Mic used in the Morrell SMC circuit model for the case where A\u00d7b is given, but Mia and/or Mic are not.  The new estimate is based on the calibration in Doll, Procemin 2016 (paper \u2116 35).\n* Removed some unnecessary messages from tent diagram display.\n\n=== 2016-11-03: Fixed bug with SGI single-stage SAG model ===\n* The P80 wasn't being used correctly with the SS SAG model using SGI.  Corrected and now appears to be working properly (thanks to Anglo American El Soldado for their Procemin paper that enabled this bug to be diagnosed).\n\n=== 2016-10-25: New single-stage SAG circuit models ===\n* Added two new models for single-stage SAG mill circuits, one based on Morrell Mi and other on Amelunxen SGI. Be careful with the SGI model as the calibration might be suspect if you are grinding below 500 \u00b5m (it should work for iron ore AG, not so sure about porphyry copper).\n* Changed the listing of model results so that only the columns that matter for a particular circuit flowsheet are showing.  The \"ball mill\" specific energy consumption doesn't show in single-stage SAG mill circuits, for example.  The exported (.ODS) spreadsheets still show all columns and in their SABC column names, so E_hpgr is actually listed as E_asag (to be fixed later).\n\n=== 2016-07-29: Mib where two WiBM records exist ===\n* The way Mib is treated has changed in the case of two WiBM records exist for the same sample (duplicate ball mill Wi tests).  The old method would draw the parameters (F80, P80, gpr, closing mesh) and calculate the Mib.  The new method calculates the Mib in the database and then accumulates Mib values.  The new method works better in the situation where one of the duplicate WiBM records has omitted the Mib parameters (accumulating NULL values works better).\n\n=== 2016-07-20: Rudimentary calculations without entering test results is now possible ===\n* Circuit calculations may now be done even if no samples are present.  This is usually done for quick prototyping or checking the expected power draw of a mill without all the fuss of entering test results. \n* The manual entry testwork fields are pre-populated with some bogus data (work index values of 10, for example) that you can change and re-run the calculations.  These changes are not stored and you'll need to re-enter any testwork changes each time a mill or a circuit setting is modified.\n\n=== 2016-07-20: Added last update date to projects view ===\n* The listing of projects now shows the date and UTC time of the last time a complete set of \"results\" was generated.  This date is not affected by changes to the mills or circuit settings, only the creation of a set of list of results for all samples will trigger the date to update.\n\n=== 2016-07-20: Database index and keys ===\n* Added more table indexes to speed up complicated queries such as parameter-versus-parameter plots.\n* Added foreign key constraints to improve back-end database maintenance.  Should not affect end users.\n\n=== 2016-06-22:  Rod Mill & Ball Mill circuit fixes, GMSG calculation ===\n* Fixes to borked RMBM circuit calculations.\n* Added RMBM circuit fed from open circuit crushing.\n* Added GMSG Bond Standard calculation to samples with Bond series of test results.\n\n=== 2016-04-22:  Added Morrell SMC & ball mill based HPGR model ===\n* Uses Morrell's Mic, Mih, Mia and Mib values to predict specific energy consumption of an HPGR circuit\n* Changed summary output \"proportion of power draw\" for crusher classes to be based on denominator of motor output power.\n\n=== 2016-02-26:  Added %solids warning to Austin model ===\n* Added a warning to Austin SAG model if %solids is outside the range of 60% to 80% solids.\n\n=== 2016-01-15:  Bug fix and more translations ===\n* Fixed a long-standing bug where the liner thickness for newly created mills reverts to the default liner thickness the second time the mill is edited.\n* Made mill model names translatable strings.\n\n=== 2016-01-10:  Testwork comparison chart ===\n* Added the Morrell '''Mib''' value to the list of available tests to view.\n* Changed the behaviour of plots where the same test is being plotted on both axis.  The single determination is used as the index key (JOIN ON `id`) instead of all permutations of the sample (JOIN ON `sampleid`).\n\n=== 2016-01-06:  Articles list now has topic filters ===\n* Added the ability to filter the list of articles so that only articles pertaining to a particular topic are shown.  Easier to browse these shorter lists.\n\n=== 2016-01-01:  Server move ===\n* Moved to an upgraded virtual server box with the latest PHP and MySQL implementation (using current stable Debian repository).\n\n===2015-11-17:  Morrell SMC model  ===\n* Fixed a bug where Morrell SMC model gave an error message and zero throughput.  (Also related to the 2015-11-08 fix to the Raw Bond model)\n\n===2015-11-11:  Bond Single Stage SAG model  ===\n* Fixed a bug where Bond SSSAG model gave an error message and zero throughput.  (The 2015-11-08 fix to the Raw Bond model broke the Bond SSSAG model)\n\n===2015-11-08:  SGI model Epeb handling ===\n* Fixed a bug where the pebble crusher specific energy consumption was not be included in the Amelunxen SGI model Etotal value\n\n===2015-10-05:  Ball mill default cone angle ===\n* Changed the default cone angle for ball mills to 15 degrees.\n\n===2015-10-05:  Report changes ===\n* Allow the user to define which percentiles should appear on a report.  The 'PDF export' button now opens a small text field where a space-delimited list of percentiles may be entered.  If this field is blank, then no \"flowsheets\" will appear in the report.\n* Added some more information to mill & PDF output pages, such as the mechanical & electrical efficiency of drives.\n\n===2015-07-24:  Synthetic Testwork results ===\n* Added a new column to several testwork tables called 'synthetic'.  If this column contains a value of '1' (boolean=true) for a test, then that test is understood to not be a real test result and is therefore not shown on the testwork comparison charts.  It is available when running circuit model simulations and does show up in the list of model results.\n\n* Fixed a bug where the motor torque for mills with qty>2 was showing the sum of the torque for all mills rather than the torque for a single mill.\n\n===2015-06-12:  Test result summary===\n* A testwork summary listing now shows the '''Mia''' and '''Mib''' values needed for the Morrell SMC model.  The '''DWI''' value was removed from the summary as it is not used directly in any of the models.\n\n* Minor changes to the PDF report showing specific energy model names rather than their ID number.\n\n===2015-06-02:  Tent Diagram===\n* A Tent diagram can now show just power, just torque, or overlay both.\n\n===2015-05-13:  Drive torque===\n* Modified the tent diagram to show the process torque demand (at the mill shell) across the range of mill speed\n* Added the torque (at the mill shell) to the list of properties in the mill detail listing.\n\n===2015-05-07:  Tent diagram===\n* Modified range of tent diagram up to 85% of critical speed.\n* Fixed bug where operating speed determined the torque of the tent diagram peak.\n\n===2015-04-25:  Added Morrell SMC (Mia, Mib) SAB & SABC circuit model===\n* New specific energy model for SAG & ball mill circuits that uses Mia (from SMC\u2122 test) and Mib (from a Bond Wi<sub>BM</sub>) values.\n* '''Must''' enter the following information for the Bond ball mill work index to permit Mib calculation in order to run this model:\n** Test P100 (closing screen) size, \u00b5m\n** Test P80 size, \u00b5m\n** Test F80 size, \u00b5m\n** Test grams per revolution (GPR)\n\n===2015-04-21:  Added rod mill-ball mill circuit model===\n* New specific energy model using Bond/Rowland method for rod mills and ball mills.\n* Fixed a problem with default values not appearing in drop-down select fields.\n* Tweaked behaviour of SGI model under SAG-limited and ball-limited conditions.\n\n===2015-04-10:  Added Amelunxen SGI model===\n* New specific energy model for SAG & ball mill circuits that uses SGI (or SPI\u2122) values instead of Bond work index for rod mill and crushing.  \n* Mandatory to set the CFsag and CFball configuration factors, see the [[Model:Amelunxen SGI|documentation]].\n\n==Bug list==\nKnown bugs that are scheduled for fixing:\n\n* SGI model PDF output does not show the CFsag and CFball values [mostly cosmetic, low priority]\n* The exported (.ODS) spreadsheets of circuit model results show columns with their SABC column names, so E_hpgr is actually listed as E_asag. Some meaningless columns (such as E_bm in a Single-Stage SAG circuit) also show.  [Mostly cosmetic, just know to change E_asag to whatever is appropriate for your flowsheet.]"
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