Ball mill work index adjustment - Revision history

Alex Doll at 14:53, 8 June 2023

2023-06-08T14:53:42Z

← Older revision		Revision as of 14:53, 8 June 2023
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	[[Category: SMC ~~model~~]]		[[Category: SMC Model]]
	[[Category: P80 adjustment]]		[[Category: P80 adjustment]]

Alex Doll: /* Comments */

2022-09-01T18:53:50Z

Comments

← Older revision		Revision as of 18:53, 1 September 2022
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	** interpolated P<sub>100</sub>, and then		** interpolated P<sub>100</sub>, and then
	** Compute & enter the ''gpr'' that gives the correct Mib value via this equation:		** Compute & enter the ''gpr'' that gives the correct Mib value via this equation:
	<math> gpr = \frac{18.18}{P_{100}^{0.295} (Mib\|new) \left[ P_{80}^{-0.295-P_{80}~~×10~~^{-6}} - F_{80}^{-0.295-F_{80}~~×10~~^{-6}} \right]} </math>		<math> gpr = \frac{18.18}{P_{100}^{0.295} (Mib\|new) \left[ P_{80}^{-0.295-P_{80} \times 10^{-6}} - F_{80}^{-0.295-F_{80} \times 10^{-6}} \right]} </math>

Alex Doll: /* Comments */

2022-04-07T00:17:47Z

Comments

← Older revision		Revision as of 00:17, 7 April 2022
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	** enter the F<sub>80</sub> observed in the test,		** enter the F<sub>80</sub> observed in the test,
	** then compute ''gpr'' from:		** then compute ''gpr'' from:
	<math>gpr = \left( \frac{44.5}{P_{100}^{0.23} \times Wi_{BM} \times 10 \left( P_{80}^{-0.5} - F_{80}^{-0.5} \right)} \right )^{\frac{1}{0.82}} </math>		<math>gpr = \left( \frac{44.5 \times 1.1023}{P_{100}^{0.23} \times Wi_{BM} \times 10 \left( P_{80}^{-0.5} - F_{80}^{-0.5} \right)} \right )^{\frac{1}{0.82}} </math>
	* If you want create a synthetic sample that gives both the interpolated '''Wi<sub>BM</sub> '''and''' Mib''', then enter		* If you want create a synthetic sample that gives both the interpolated '''Wi<sub>BM</sub> '''and''' Mib''', then enter
	** the interpolated Wi<sub>BM</sub>,		** the interpolated Wi<sub>BM</sub>,

Alex Doll at 18:33, 6 March 2022

2022-03-06T18:33:41Z

← Older revision		Revision as of 18:33, 6 March 2022
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	[[Category: P80 adjustment]]		[[Category:P80 adjustment]]
	[[category:Testwork]]		[[category:Testwork]]
	The Bond ball mill work index test requires the operator to select an appropriate screen size to "close" the test. The procedure states that the closing screen size should be such that the product size of the test is the same as the expected product size of the operating plant. If the tests were done at the wrong closing screen size, then a ball mill work index adjustment may be required.		The Bond ball mill work index test requires the operator to select an appropriate screen size to "close" the test. The procedure states that the closing screen size should be such that the product size of the test is the same as the expected product size of the operating plant. If the tests were done at the wrong closing screen size, then a ball mill work index adjustment may be required.
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	[[Category: ~~Morrell~~ ~~Mib~~]]		[[Category: SMC model]]
	[[Category: P80 adjustment]]		[[Category: P80 adjustment]]

Alex Doll: /* Ball mill work index adjustment */

2022-03-06T18:25:26Z

Ball mill work index adjustment

← Older revision		Revision as of 18:25, 6 March 2022
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	# Perform the laboratory program on a one or two representative samples to determine the Hukki Exponent (-a).		# Perform the laboratory program on a one or two representative samples to determine the Hukki Exponent (-a).
	# Enter this (a) value (without the minus sign) into the '''Circuit Settings''' of a Bond specific energy model. The software will automatically adjust all compatible test results using this exponent.		# Enter this (a) value (without the minus sign) into the '''Circuit Settings''' of a Bond specific energy model. The software will automatically adjust all compatible test results using this exponent.

			Only samples where the '''F80''', '''P80''', and '''gpr''' values are entered into the project testwork database can be adjusted. Any sample that is missing any of these parameters will not be adjusted.

	===What the SAGMILLING.COM software does (Bond Wi version)===		===What the SAGMILLING.COM software does (Bond Wi version)===

Alex Doll: /* Laboratory program needed to perform adjustment */

2022-03-06T18:22:54Z

Laboratory program needed to perform adjustment

← Older revision		Revision as of 18:22, 6 March 2022
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	[[File:SignaturePlots.png]]		[[File:SignaturePlots.png]]

			Example using the Josefin & Doll published signature plot:
			* The exponent ''a'' for Bond equations is 0.535 and the exponent ''a'' for Morrell equations is 0.666. This is the value that is entered into the Circuit Configuration settings.
			* The coefficient ''K'' for this sample is 220 for Bond models and 451 for Morrell models. This coefficient is not entered, the software automatically computes it when the ''a'' value is specified.

	==Ball mill work index adjustment==		==Ball mill work index adjustment==

Alex Doll: /* Ball mill work index adjustment */

2022-03-06T18:22:07Z

Ball mill work index adjustment

← Older revision		Revision as of 18:22, 6 March 2022
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	==Ball mill work index adjustment==		==Ball mill work index adjustment==
	[[Category: Bond work index]]		[[Category: Bond work index]]
	Perform the laboratory program on a one or two representative samples to determine the Hukki Exponent (-a). ~~Enter this (a) value (without the minus sign) into the '''Circuit Settings''' of a Bond specific energy model. The software will automatically adjust all compatible test results using this exponent.~~		# Perform the laboratory program on a one or two representative samples to determine the Hukki Exponent (-a).
			# Enter this (a) value (without the minus sign) into the '''Circuit Settings''' of a Bond specific energy model. The software will automatically adjust all compatible test results using this exponent.

	Example using the Josefin & Doll published signature plot:
	* The exponent ''-a'' for Bond equations is -0.535 and the exponent ''-a'' for Morrell equations is -0.666. This is the value that is entered into the Circuit Configuration settings.
	* The coefficient ''K'' for this sample is 220 for Bond models and 451 for Morrell models. This coefficient is not entered, the software automatically computes it when the ''-a'' value is specified.

	===What the SAGMILLING.COM software does (Bond Wi version)===		===What the SAGMILLING.COM software does (Bond Wi version)===

Alex Doll: /* Morrell Mib adjustment */

2022-03-06T18:21:34Z

Morrell Mib adjustment

← Older revision		Revision as of 18:21, 6 March 2022
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	==Morrell Mib adjustment==		==Morrell Mib adjustment==
			# Perform the laboratory program on a one or two representative samples to determine the Hukki Exponent (-a).
	This section describes what the software does, you only need to enter the correct ''-a'' for a Morrell equation and all the following will be handled by the program.
			# Enter this (a) value (without the minus sign) into the '''Circuit Settings''' of a Bond specific energy model. The software will automatically adjust all compatible test results using this exponent.

			===Theory behind performing an adjustment===

	The Morrell Mi equations are in the form of Hukki's Conjecture, so the adjustment procedure is also valid for adjusting an Mib value to a different particle size if you have measured the ore's exponent ''a''. It follow the similar process to the Wi correction where a Hukki exponent is determined in 3+ Bond ball mill grindability determinations using Morrell's equation for the specific energy term, then Hukki's equation is solved for constant K at the tests' P<sub>80</sub> values		The Morrell Mi equations are in the form of Hukki's Conjecture, so the adjustment procedure is also valid for adjusting an Mib value to a different particle size if you have measured the ore's exponent ''a''. It follow the similar process to the Wi correction where a Hukki exponent is determined in 3+ Bond ball mill grindability determinations using Morrell's equation for the specific energy term, then Hukki's equation is solved for constant K at the tests' P<sub>80</sub> values

Alex Doll: /* Ball mill work index adjustment */

2022-03-06T18:19:59Z

Ball mill work index adjustment

← Older revision		Revision as of 18:19, 6 March 2022
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	The Morrell Mib value also requires an appropriate choice of screen, and it is usually more sensitive to variation in P80 than the Bond work index.		The Morrell Mib value also requires an appropriate choice of screen, and it is usually more sensitive to variation in P80 than the Bond work index.

	==~~Ball~~ ~~mill~~ ~~work~~ ~~index~~ adjustment==		==Laboratory program needed to perform adjustment==
⚫	[[Category: Bond work index]]

	Adjustment procedure using the [[Bibliography: Testwork programs\|Josefin equation]] is conducted as follows:		Adjustment procedure using the [[Bibliography: Testwork programs\|Josefin equation]] is conducted as follows:

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	[[File:SignaturePlots.png]]		[[File:SignaturePlots.png]]

			==Ball mill work index adjustment==
		⚫	[[Category: Bond work index]]
			Perform the laboratory program on a one or two representative samples to determine the Hukki Exponent (-a). Enter this (a) value (without the minus sign) into the '''Circuit Settings''' of a Bond specific energy model. The software will automatically adjust all compatible test results using this exponent.

			Example using the Josefin & Doll published signature plot:
	* The exponent ''-a'' for Bond equations is -0.535 and the exponent ''-a'' for Morrell equations is -0.666. This is the value that is entered into the Circuit Configuration settings.		* The exponent ''-a'' for Bond equations is -0.535 and the exponent ''-a'' for Morrell equations is -0.666. This is the value that is entered into the Circuit Configuration settings.
	* The coefficient ''K'' for this sample is 220 for Bond models and 451 for Morrell models. This coefficient is not entered, the software automatically computes it when the ''-a'' value is specified.		* The coefficient ''K'' for this sample is 220 for Bond models and 451 for Morrell models. This coefficient is not entered, the software automatically computes it when the ''-a'' value is specified.

	What the software does (Bond version):		===What the SAGMILLING.COM software does (Bond Wi version)===
		⚫	The laboratory ball mill work index result is read from the database (P<sub>80</sub>, P<sub>100</sub>, F<sub>80</sub>, and ''gpr''; if multiple results exist with a particular sample name, then the averages of each parameter are used). The value ''K'' is determined for the sample, the parameter ''-a'' is read from the Circuit Settings, and the P<sub>80\|adjusted</sub> is read from the simulation model (the P<sub>80</sub> displayed at the top-left of the Flowsheet page, which might be different to the target P<sub>80</sub> entered in the Circuit Settings).
⚫	* Compute K values for ~~each~~ grindability result:

		⚫	* Compute K values for an individual grindability result:
	<math>K = \frac{10 \times Wi_{test} \times (P_{80\|test}^{-0.5} - F_{80}^{-0.5})}{P_{80\|test}^{-a}}</math>		<math>K = \frac{10 \times Wi_{test} \times (P_{80\|test}^{-0.5} - F_{80}^{-0.5})}{P_{80\|test}^{-a}}</math>
⚫	* ~~Then compute the~~ adjusted work index ~~each~~ grindability result ~~using~~ the ''K'' value:
⚫	<math>Wi_{adjusted} = \frac{K_{test} \times P_{80\|adjusted}^{-a}}{10 \times (P_{80\|adjusted}^{-0.5} - F_{80}^{-0.5})}</math>

			The ''Wi<sub>adjusted</sub>'' is computed using the equation below.
	===What the SAGMILLING.COM software does (Bond Wi version)===

		⚫	* The adjusted work index for an individual grindability result uses the ''K'' value:
⚫	The laboratory ball mill work index result is read from the database (P<sub>80</sub>, P<sub>100</sub>, F<sub>80</sub>, and ''gpr''; if multiple results exist with a particular sample name, then the averages of each parameter are used). The value ''K'' is determined for the sample, the parameter ''-a'' is read from the Circuit Settings, and the P<sub>80\|adjusted</sub> is read from the simulation model (the P<sub>80</sub> displayed at the top-left of the Flowsheet page, which might be different to the target P<sub>80</sub> entered in the Circuit Settings). ~~The ''Wi<sub>adjusted</sub>'' is computed using the equation above.~~
		⚫	<math>Wi_{adjusted} = \frac{K_{test} \times P_{80\|adjusted}^{-a}}{10 \times (P_{80\|adjusted}^{-0.5} - F_{80}^{-0.5})}</math>

Alex Doll: /* What the SAGMILLING.COM software does (Bond Wi version) */

2022-03-06T18:11:54Z

What the SAGMILLING.COM software does (Bond Wi version)

← Older revision		Revision as of 18:11, 6 March 2022
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	===What the SAGMILLING.COM software does (Bond Wi version)===		===What the SAGMILLING.COM software does (Bond Wi version)===

	The laboratory ball mill work index result is read from the database (P<sub>80</sub>, P<sub>100</sub>, F<sub>80</sub>, and ''gpr''; if multiple results exist with a particular sample name, then the averages of each parameter are used). The value ''K'' is determined for the sample, the parameter ''-a'' is read from the Circuit Settings, and the P<sub>80\|~~new~~</sub> is read from the simulation model (the P<sub>80</sub> displayed at the top-left of the Flowsheet page, which might be different to the target P<sub>80</sub> entered in the Circuit Settings). The ''Wi<sub>adjusted</sub>'' is computed using the equation above.		The laboratory ball mill work index result is read from the database (P<sub>80</sub>, P<sub>100</sub>, F<sub>80</sub>, and ''gpr''; if multiple results exist with a particular sample name, then the averages of each parameter are used). The value ''K'' is determined for the sample, the parameter ''-a'' is read from the Circuit Settings, and the P<sub>80\|adjusted</sub> is read from the simulation model (the P<sub>80</sub> displayed at the top-left of the Flowsheet page, which might be different to the target P<sub>80</sub> entered in the Circuit Settings). The ''Wi<sub>adjusted</sub>'' is computed using the equation above.