Mac + AccuRate = Schenck Process

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Reports on “Parts and Services”

Baghouse Services Utilize 40 Years of Experience

With over 40 years of dust collection experience, our Baghouse Service Program helps customers lower emissions and meet EPA standards. Experienced technicians and trained crews handle inspections, bag changes, repairs, installations both new & used, flow studies, conversions and more for any size dust collector or brand.
Benefits of Baghouse Service Program:
Extended life of bags

  • Lower emissions
  • Reduced downtime
  • Reduced in-house maintenance costs
  • Improved plant sanitation and employee satisfaction
  • Minimized plant liability
  • Reduced operational costs
  • Reduced spare parts inventory

Tech Tips:
Monitoring the Differential Pressure of Your Baghouse
Tips from Schenck Process Service Technicians to ensure your equipment continues to run accurately and efficiently.

  • The differential pressure reading is a simple way to get a quick assessment of how your baghouse is running. It is important to monitor the pressure differential of your baghouse on a regular basis (at least once a day), and make sure the pressure differential gauge is working correctly.
  • If there are any sudden changes in the pressure differential, whether up or down, first make sure the two lines connecting the gauge are not plugged, crimped or damaged.
  • If the gauge is reading “normal” range, and there are no emissions visible, the filter is running properly. If, however, you begin to notice an upward creep in the pressure differential, it can be an indication that the filter bags are beginning to plug and may need to be replaced.
  • If there is sudden upward spike in pressure differential, it is usually symptomatic of an upset condition in the baghouse (for example, a sudden influx of moisture-laden air that decreases bag permeability) or possible problems with the bag-cleaning system.
  • If there is a sudden decrease in pressure differential, often accompanied by visible emissions, may indicate actual failure of one or more filter bags.
  • If you have any questions please contact our Baghouse Service group at 800-821-2476.

Schenck Process Crossword Puzzle
Test Your Material Handling Knowledge
Schecnk_Process_Crossword_Puzzle
Complete this puzzle and send it to mktg@schenckprocess.com for your chance to win a $100 VISA gift card. Winner will be determined by the most correct answers. In case of a tie a drawing will be held to determine a winner.


Tech Tips:MECHATRON Feeders
Tips from Schenck Process Service Technicians to ensure your equipment continues to run accurately and efficiently.

  • Make sure your flex hopper clamp is above the guide pin on the front of the hopper. This ensures material will never leak from the flex hopper connection.
  • Do not use any chlorine based cleaners on the flexible hopper. If you have questions check with the Schenck Process Service department to make sure you’re cleaner is approved.
  • Make sure your inlet and discharge connections always have a little bit of slack. A feeder on load cells should be “floating.”
  • If in gravimetric mode make sure the feeder remains untouched. Bumping or resting on the feeder while its running can greatly influence the load cells and flow rate.
  • If changing to a new material, contact the Schenck Process Service department to help verify your helix is capable of your required rates.
  • If you have any questions please contact our Technical Service group at 888-742-1249 x3.

Schenck_Process_Mechatron_Feeder


Repair Program Extends Product Life
The Schenck Process Equipment Repair Program helps customer minimize costs, and avoid downtime. Repair work can be done on a wide range of equipment, for both Schenck AccuRate and Mac Process product lines.
Our Whitewater, WI Repair Center offers repairs on Schenck Process weighing and feeding equipment such as: feeders and weighfeeders, load cell modules, counterbalance scales, platform scales, mass flow meters, IDMS valves, iris valves, and controls. Schenck Process service personnel are available for on and off-site repairs and equipment exchange during times of repair. When available, refurbished equipment can be exchanged or rented during times of repair, reducing plant downtime.

Schenck_Process_Repair_Shop

The Valve Rebuild Center located in Sabetha, KS, restores airlocks and vales to peak performance. Services offered include: re-machining of castings, replacement of components (seals, o-rings, package bearings, and shaft blades), sandblasting, painting, re-anodizing, and new actuator packages. Schenck Process technicians will conduct a full inspection of equipment and will send a detailed estimate. Refurbished valves are returned in like-new condition and come with a 1 year warranty.
Schenck_Process_Valve_Rebuild_Center


About Schenck Process
The name Schenck Process is synonymous with more than 125 years of experience and is a strong brand. Originally founded as an iron foundry and weighing machine factory, it has grown to become one of the global market leaders in applied measuring and process technology. In 22 countries on five continents, more than 3,200 employees are developing innovative solutions for weighing, feeding, conveying, screening, automation and air filtration technology processes. The members of the Schenck Process Group are: Schenck Process, Schenck AccuRate, Stock, Redler, Fairfield, Screenex, Pentec, Clyde Process and Mac Process.

 

Coperion K-Tron at Fakuma 2014

Coperion K-Tron cordially invites you to attend Fakuma 2014, Oct 14-18, 2014 in Friedrichshafen, Germany, Booth 6406, Hall A6 to learn more about the latest advances in feeding, weighing and pneumatic conveying solutions.

We will show you the patented BSP-135 Bulk Solids PumpTM Feeder on pivoting base frame which has been specially designed and engineered to provide gentle, precise feeding of free-flowing pellets, granules, and friable bulk materials.

Additionally on display will be a Gravimetric Batch Blender with integrated 2400 Series Vacuum Receivers and a Twin Screw Powder Feeder.

Stop by the booth and explore our innovative solutions.

We look forward to seeing you at Fakuma 2014!

Your team of Coperion K-Tron
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Bulk Solids PumpTM for precise feeding of free flowing bulk materials

First in the Industry: Positive Displacement Feeding Technology

 

The new Coperion K-Tron Bulk Solids Pump (BSP) feeders have been specifically designed and engineered to provide gentle, precise feeding of free-flowing materials

The Features

Coperion K-Tron Bulk Solids Pump (BSP) feeders have been specifically designed and engineered to provide gentle, precise feeding of free-flowing pellets, granules, and friable products.

Preview animations and video

The BSP feeders do not use the usual screws/augers, belts or vibratory trays to convey the material. The feeder utilizes positive displacement action to feed free flowing materials with astounding accuracy, offering uniform discharge, consistent volume and gentle handling.

The BSP feeders have vertical rotating discs that create a product lock-up zone, conveying the material smoothly from storage hopper to discharge outlet, achieving true linear mass flow.

Utilizing a simple design and the principle known as “lock up” (see demonstration), the material in the feeder is moved together in true positive displacement, producing excellent linearity and breakthrough accuracy levels.

With no pockets or screws and only one moving part, the compact feeder is cleaned in seconds, making it ideal for applications with frequent material changes.

 

Download the BSP brochure

Bulk Solids Pump Feeders:
Brochure highlights the features, principle of operation and anatomy of the Coperion K-Tron Bulk Solids Pump feeder line, including information on “Positive Displacement Feeding”, as well as information on various feed rates / models available.
picture of the 4 zones of a Bulk Solids Pump feeder

The Principle

Zone 1: CONSOLIDATION
Interparticle forces produce lock-up at the end of Zone 1

 

Zone 2: ROTATION
Material is in lock-up condition throughout Zone 2 and rotates as a solid body

 

Zone 3: RELAXATION
Interparticle forces fall below lock-up threshold

 

Zone 4: ACTIVE DISCHARGE
Material discharge occurs.

 

BSP technology demonstrations and video

The Anatomy of the BSP-100 and BSP-135

exploded view of BSP-100 and BSP-135

 


BSP-100

The BSP-100 features a single feeding duct formed by two rotating discs. It includes a conical inlet transition piece which can be combined with a variety of standard extension hoppers.

A slide gate on the inlet allows for material shut-off and removal of feeder for cleaning and hopper emptying. A low power stepper motor drive mechanism and controller provide excellent turndown and flexibility ensuring a very wide operating range.

 

The BSP-100 is designed for feed rates of 2 to 400 dm³/hr (0.07 to 14 ft³/hr). It is available as a volumetric unit or as a gravimetric unit with a choice of 2 platform scales, single point suspension scale or three-point suspension scale.

 


BSP-135

The BSP-135 is a slightly larger version of the BSP-100, with all the same features except that it has three feeding ducts instead of one.

The BSP-135 is designed for feed rates of 22 to 4,400 dm³/hr (0.8 to 155  ft³/hr).

Unit is available as volumetric or as gravimetric, with a choice of platform scale, single-point suspension scale, or three-point suspension scale.

 


BSP-150-S

BSP-150-S is designed with four feeding ducts, and is based on the same technology as the BSP-100, but manufactured of stainless steel.

The unit is designed with an inlet transisiotn piece, as well as a stepper motor and removable material discharge chute.

With only one moving part and no pockets or screws, the design provides ease of use and almost zero maintenance.

The BSP-150-S is designed for feed rates of 34 to 6,700 dm³/hr (1.2 to 237 ft³/hr).

It is available as a volumetric unit or as a gravimetric unit with a three-point suspension scale.

 


 

Benefits of the Revolutionary BSP Technology

  • True Positive Displacement Action
  • Linear Over Full Operating Range
  • Uniformity of Discharge
  • Active Discharge (minimal residual material)
  • Unaffected by Differential Pressures
  • Mechanical & Maintenance Simplicity

For video, animated demonstrations, brochures and technical articles click here.

 

Gravimetric Batch Blenders

Coperion K-Tron Gravimetric Batch Blenders are available in various sizes from 0.5 kg to 25 kg total batch size and include up to 8 main feed elements depending on the unit.

Application

Each one of the materials is dispensed sequentially into a common weighing hopper in the desired proportions. The weighed materials are then released into a separate mixing chamber, which provides a consistent homogeneous blend. It includes an advanced metering and weighing system that accurately controls every ingredient of every batch to the desired amounts and is not averaged over multiple batches.

Gravimetric Batch Blenders Design Features

The Coperion K-Tron range of blenders are compact with a robust design. They are designed and constructed of heavy gauge steel (11 gauge steel) to withstand the most rigorous of operating conditions. The load cell is overload protected and guarded from physical damage. Each blender is constructed with high load bearing continuous welding and is protected against vibration and shocks. All blenders include self-optimizing software to give you the most efficient output on every recipe. Continuous mixing of the bulk materials means the mixing times do not need to be adjusted and the consistency of every mix is guaranteed.

Standard Mechanical Specifications

  • Ingredient accuracy of +/- 0.02% per batch at highest accuracy setting
  • Robust design (11 gauge steel)
  • Color touch screen
  • 3 level password security
  • Ethernet port with remote service capability
  • 2 USB ports
  • Integrated loading platform for mounting material loaders/vacuum receivers
  • Simple quick drain models
  • Integrated slide valves on each material hopper
  • Side feeders – up to (4) available on most models

 

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For more information on Coperion K-Tron, please click here.

For more information on Coperion, please click here.

Keywords:
bulk-online Leader, Mechanical Feeders, Agitated Feeders, Dosing Feeders, Gravimetric Feeders, Loss-in-Weight Feeders, Proportioning Feeders, Sanitary Feeder, Screw Feeders, Vibratory Feeders, Volumetric Feeder, Weigh Belt Feeders, Pneumatic Conveyors, Modes of Pneumatic Conveying, Dilute Phase Conveying, Vacuum Conveying, Process Automation, Silo Storage Equipment & Systems, Silo Discharge Equipment, Live Bottom Flow Devices, Pneumatic Flow Devices, Weighing & Proportioning Equipment, Weigh Feeders, K-Tron Feeders: Volumetric & gravimetric feeders, K-Tron Premier: pneumatic conveying equipment

 

Watch this video

 

Coperion K-Tron is a  bulk-online Leader

Playing with Fire? A Guide to Fire Retardant Conveyor Belts

September 2014

If a belt does not perform according to the manufacturer’s claims by wearing prematurely, ripping too easily, disintegrating due to excessive heat or because of oil penetration, the risk to life and limb is relatively small. But if a conveyor belt that is specified as being fire resistant catches fire but does not resist the fire the way that it should do then it will literally ‘convey’ the fire throughout the site. The consequences can be catastrophic.

 

Is cost being put before safety? 

Due to the financial pressures, more and more organisations are being forced to examine their day-to-day running costs and, almost inevitably, seek cost savings. The pressure to cut costs seems to be influencing buying decisions concerning fire resistant conveyor belts but is price being put before safety? The discovery that a belt is not sufficiently fire retardant is only likely to be made when it is too late.

Anecdotal as well as factual evidence gained from extensive laboratory testing certainly indicates that even some of the biggest users of conveyor belts are using belts that are not as resistant to fire as they are claimed to be. In a growing number of instances, many bulk material handling sites that should be using fire resistant belting are operating with non-fire resistant belts simply in the pursuit of ‘economy’.

At the same time, insurance companies are becoming increasingly concerned. According to at least one major insurer, claims for fires directly involving conveyor belts are costing an average of nearly $8 million per claim. To find out more about this highly important and complex subject we sought the guidance of the chairman of the international standards (ISO and CEN) committee and one of the world’s leading authorities in conveyor belting, Sytze Brouwers.

No conveyor belt is fire proof

Fire resistant standards for test methods and specifications applied to conveyor belts are becoming increasingly stringent and can be very confusing. The first and most important thing to bear in mind is that conveyor belts cannot be totally fire proof. Using special additives and chemicals, the rubber used in the top and bottom covers that protect the carcass of the belt and the rubber skim between the fabric plies of the carcass can be engineered to resist fire but the complete structure of the belt cannot be made fire proof. The fabrics used in the carcass of the belt most commonly contain polyester and nylon, which have virtually no resistance to fire. In other words, every belt will begin to burn (and continue to burn) when exposed to a naked flame that has sufficient energy to ignite the belt.

 

What is meant by ‘fire resistance’?

Once a belt is ignited by flame then it will continue to burn until it is no longer exposed to the source of ignition. Although commonly referred to as ‘fire resistance’ within the conveyor belt industry, in real terms it is the ability of specifically designed rubber to self-extinguish once the source of ignition is no longer present.

 

Environments with inflammable dust and gas

EN 12882 is the standard for safety requirements for conveyor belts for general-purpose use (not underground). The most basic electrical and flammability safety requirement is EN 12882 Category 1. For environments where dust or other potentially combustible materials are involved, it is essential that the conveyor belt cannot create static electricity that could ignite the atmosphere. Belts need to be able to allow static electricity to pass through the metal frame of the conveyor structure down to earth rather than allow static to build up. At Dunlop we decided some time ago that the safest approach was for all of our belts to be anti-static and conform to EN/ISO 284 international standards. This means that they can all be used in ATEX 95 (94/9/EC Directive) classified zones. Some people mistakenly believe that all belts used in ATEX classified zones must be flame retardant but actually this is not the case.

ATEX regulations apply to industrial environments where there is a risk of explosion because dust or gas is present in the atmosphere. For those organizations that are buying conveyor belts for use in ATEX regulated areas it is very important to ask potential suppliers for a copy of a certificate provided by an appropriate independent testing authority such as the German Institute Dekra Exam GmBH.

DIN 2218 testing at Dunlop
DIN 2218 testing at Dunlop

 

Test method EN 12881 Part 1. Mid Scale method C
Test method EN 12881 Part 1. Mid Scale method C

Above-ground and general service applications

Because fire safety is such an important issue there are numerous safety classifications and international standards for which there are many different tests used to measure the self-extinguishing properties of conveyor belts. Rubber belts reinforced by layers of textile fabrics (multi-ply) or steelcord reinforcement are the most commonly used type above ground and in general service applications. The basis of most tests for belting used in normal industrial applications is EN/ISO 340. This standard makes the distinction between fire resistance with covers (K) and fire resistance with and without covers (S).

The relevance of “with and without covers” is that as belt covers wear during their operational life the amount of fire resistant rubber protecting the flammable carcass reduces. The best way to decide between ‘K’ and ‘S‘ grades is to consider the material being carried. For moderately abrasive materials then ‘K’ grade is usually perfectly adequate. This also applies to elevator belts. However, if the material is abrasive and tends to wear the top cover quite rapidly then the safest option is be to choose the ‘S‘ grade.

In both ‘K’ (EN 12882 Class 2A) and ‘S’ (EN 12882 Class 2B) grades, the rubber skim that bonds the fabric layers of the carcass together should also be fire resistant. In the case of ‘S’ grade (fire resistant without covers), the rubber skim should be thicker than the skim used for ‘K’ grade. The easiest way to tell if a ‘K’ grade belt has the required thicker rubber skims is to obtain technical datasheets from the manufacturer for both ‘S’ grade and ‘K’ grades and compare the carcass thickness figures.

Another reason why buyers should always request technical datasheets before placing an order is that they include information on the level of abrasion (wear) resistance. The ingredients used to create a fire resistant rubber compound generally have an adverse effect on its wear resistant properties. Consequently, fire resistant belts tend to wear faster and as the thickness of the rubber reduces so does the level of protection given to the inflammable carcass. To avoid premature belt replacement, in the case of purely fire resistance belting, buyers should always demand an average abrasion resistance level of no more than 150mm³.

ISO 340 testing
ISO 340 testing

At Dunlop our rubber compound technicians have proved that it is possible to have the best of both worlds by developing a fire resistant rubber that also has good resistance to abrasion. In fact our technicians have created a compound that has 50% better wear resistance than the DIN Y standard for abrasion resistant rubber. This means that the belt retains its resistance to fire for much longer and at the same time extends the operational lifetime by the same proportion. However, laboratory tests have revealed that this is very much an exception to the rule within the conveyor belt industry.

Poor quality fire resistant belt can be expensive!
Poor quality fire resistant belt can be expensive!EN/ISO 340 testing

EN/ISO 340 tests involve exposing 6 individual samples of belt to a naked flame causing them to burn. The source of the flame is then removed and the combustion time (duration of flame) of the test piece is recorded. A current of air is then applied to the test piece for a specified time after the removal of the flame. The flame should not re-ignite.

The time it takes for the belt sample to self-extinguish is then measured. The duration of continued burning (visible flame) should be less than 15 seconds for each sample with a maximum cumulative duration of 45 seconds for each group of six tests. This factor is of paramount importance because it determines how fire can be effectively carried along a moving belt. The effects of fire being literally ‘conveyed’ to adjoining buildings can be seen in some of the photographs.

Even if a manufacturer states that their fire resistant belt has passed the ISO 340 test, the buyer should still exercise caution. A typical conveyor belt can easily travel more than 40 meters within the 15 seconds sufficient for a belt sample to pass the test but which would still allow the belt to carry flames over a potentially dangerous distance. For this reason our required time limit standard in Dunlop is no more than one second, ideally 0 seconds. Buyers of fire resistant belt are therefore recommended to ask to see copies of the test results and to check that the laboratory that has carried out the tests has EN ISO 17025 certification.

What standard of fire resistance do I need?

 When choosing a fire resistant conveyor belt, establishing the correct level or standard of fire resistance needed for a specific application or environment is of crucial importance. This can present one of the most difficult challenges for users of conveyor belts. For the vast majority of belts being used in the open air, Class 2A or 2B would be perfectly adequate. Class 2A demands that the belt is able to pass the ISO 340 test described earlier with the covers intact on the belt samples (K grade). Class 2B requires that the belt that can also pass the ISO 340 test with the top and bottom cover rubber removed (S grade). As mentioned earlier, the electrical conductivity of the belt also needs to fulfill the requirements of ISO 284.

If you are still unsure of the fire resistant grade of belting needed then it is best to carry out an internal risk assessment. If the expertise for this does not exist within your company then there are a number of external organizations (and almost certainly your insurers) that can perform this function for you.

For conveyors carrying materials that contain oil such as wood chips and biomass (some types can spontaneously combust), rubber compounds that are resistant to fire, abrasion and oil are available. There are, of course, two types of oil resistance – mineral and vegetable. This is yet another important consideration when deciding on the correct type of fire resistant belt so buyers are recommended to be very specific when making requests for quotations from manufacturers and suppliers.

 

Dunlop BV XS conveyor
Dunlop BV XS conveyor

CEN fire test standards

One of the most problematic aspects of fire testing rubber conveyor beltsfor industrial use above ground is that most of the test methods were established many years ago specifically for underground mining belts. Enormously complex and very costly testing has to be made by independent testing institutions. Because of environmental regulations, large-scale gallery fire tests now involve using a 12-meter long container filled with carbon to filter the smoke emissions before being released into the atmosphere. In order to be awarded a safety standard certificate every belt type has to be independently tested. For some tests a minimum of 20 meters of belt is needed

Such tests can easily cost up to 20,000 euros or more. For the manufacturers of solid woven underground mining belts and steelcord belting this is not a particularly big problem because there are a relatively small number of different belt types that have to be supplied for testing in large quantities. Although the test certificates are valid for several years, these large-scale tests present a huge and costly problem to manufacturers of rubber belting for above ground use because there is a much wider range of belt types. Such complex test methods have made it extremely difficult to develop improved levels of fire safety because if a belt sample fails the tests then the technicians have to go back to the drawing board to make further changes to the rubber compound and then embark on another round of expensive tests.

Apart from hindering development of fire resistant belting, it also means that it is very difficult to adequately test those belts that manufacturers claim reach specific levels of fire resistance. This is one of the reasons why there are so many end-users operating conveyors fitted with belts that provide totally inadequate levels of fire safety.

 

New CEN fire test standards to be introduced

The problem has long been recognised by the CEN standards committee and over recent years they have been trying to find a solution. Following recent meetings attended by technical experts from all over Europe, the Committee European de Normalization will be introducing several positive changes in 2014.

Agreement has been reached on using and adapting tests already in existence for quality standards such as DIN and BS that will involve much smaller scale tests using much smaller equipment. This will mean that major manufacturers will be able to experiment and carry out testing in their own laboratories. Ironically, these new test methods will actually be even more demanding than the old, large-scale tests. Major insurance companies are already showing interest and are becoming involved in discussions. For them, and for all genuinely safety conscious organisations, this can only be very good news.

 

Don’t play with fire

Although manufacturers and suppliers may be able to provide test certificates, in some cases the certificate may only relate to the belting that the manufacturer produced for test certification purposes. In reality, the actual belt delivered to site may well not be up to the required standard. For greater peace of mind we would suggest ordering an extra meter of belt and then have that piece of belt tested by an accredited testing authority or laboratory.

The price of not exercising caution simply cannot be calculated.

 

 

The author: Sytze Brouwers is the Chief Application Engineer for Fenner Dunlop BV (Dunlop Conveyor Belting) in The Netherlands.

Fenner Dunlop Group on the Portal 

 

The New Bulk-Blog

Dear Bulkoholics,

As you may have noticed, we are presently upgrading our bulk-online system and our front page, and in this context we will also put more emphasis on the Bulk-Blog. We intend to invite major companies, institutions, organisations and publications to present their News. By doing so, we will offer them a platform on the worldwide leading Powder/Bulk Portal. This should be of interest to them and it will certainly be of interest to our many readers and users around the world.

Should you be interested in using this plattform, please post your message/comment here or write to wohlbier@bulk-online.com.

I am very excited about this new development and believe that it could be of considerable value to our members.

Reinhard Wohlbier

 

Unscrambling the French sampling school

Dr Pierre M Gy (1932- ) threaded together the theory and practice of sampling particulate materials. Gy’s gift to mankind ended on my desk about Christmas 1979. I had never ordered it! Yet, Gy’s invoice had come along with his work. Elsevier Scientific Publishing Company had printed it as Sampling of Particulate Materials, Theory and Practice. It had done so as Developments in Geomathematics 4.

Elsevier has ranked Dr F P Agterberg’s Geomathematics as Volume 1 in this series. Dr M David’s Geostatistical Ore Reserve Estimation was ranked as Volume 2. I kept track of what Elsevier Scientific Publishing Company had deemed fit to print before 1979. I am keeping my favorite textbooks close together. William Volk’s Applied Statistics for Engineers is my favorite. Of course, Volk’s work ought to be studied in detail. Degrees of freedom should be counted whenever unbiased confidence intervals and ranges for contents and grades ought to be reported!

Dr Gy never got into partitioning sets of primary increments into pairs of interleaved primary samples. A single degree of freedom is awarded when a pair of interleaved primary increments is selected but one is still better than none. Degrees of freedom abound in Gy’s work but fail to show up in his Index. Gy refers to “degenerate splitting processes” and “degree of representiveness” but neither is defined in his very own textbook. Professor George Matheron stripped the variance off the distance-weighted average AKA kriged estimate.Functions without variances? Good grief!

Dr Gy postulated ad verbatim under Introduction on the first page:

“The failure of mining or metallurgical undertakings can nearly always be traced back to the confusion between “specimens” on the basis of which no sane financial decision should ever be made and “samples” known to be representative of the object to be valued (ore body, shipments of ores or concentrates, etc..) within the limits of a certain confidence interval that can be estimated and relied upon. In other word, the failure of what is aptly called a mining or metallurgical “venture” can nearly always be attributed to unaccountable sampling errors”.

Dr Pierre M Gy does refer to Geostatistical Ore Reserve Estimation. It was Dr Michel David who had put it on paper. All it took was to strip the variance off the distance-weighted average and call what was left a kriged estimate. Elsevier Scientific Publishing Company deemed it fit to print and had done so in 1977.

 

Who’s still oversmoothing small blocks?

Professor Dr Margaret Armstrong and Professor Dr Roussos Dimitrakopoulos rank amongst  the most gifted geostatistocrats on our little planet. What a shame that they smooth data sets beyond the perfect fit! Dr RD is into stringing Markov chains between measured values! What he should not do is assume spatial dependence between measured values in ordered sets. What he ought to do is count degrees of freedom. Stringing Markov chains does not create spatial dependence anywhere in this universe!

Optimierung an der Deponie Tüfentobel

Verlängerung RopeCon Tüfentobel

In der Deponie Tüfentobel transportiert ein RopeCon seit 2005 Inertmaterialien entlang eines langgestreckten Tals, das hinterfüllt werden soll. Das Band entlädt die Inertmaterialien direkt dort, wo sie eingebaut werden sollen, auf einen Schüttkegel. Im März 2013 wurde eine neue Stütze entlang der Strecke eingebaut und der Abwurfpunkt versetzt. Der folgende Artikel berichtet zunächst über diese Verlängerung und beschreibt außerdem die allgemeinen Auswirkungen des Einsatzes dieses Transportsystems auf den Betrieb der Deponie.

Read more

A study on kriging small blocks

Professor Dr Margaret Armstrong ranks high amongst geostatistical scholars. In contrast, Mr Normand Champigny has earned a Certificate of sorts and turned into a gifted CIM Member. CIM Bulletin published this small block study in March 1989. What the authors had discovered was that “kriged estimates for very small blocks are over-smoothed”, and that “mine planners often insist on kriging very small blocks!” Good grief! The problem is not so much that mine planners have not been taught how to test for spatial dependence between measured values in ordered sets. The real problem is that Professor Matheron did not know how to test for spatial dependence between measured values, and how to count degrees of freedom! So it was not at all surprising when Matheron flunked his PhD thesis in 1970! Yet, in 1974 Matheron was ready to teach “Brownian motion along straight lines!” He has been hailed as the Founder of Spatial Statistics! For crying out loud!

Professor Dr Margaret Armstrong had figured out what Matheron had failed to grasp! After completing a Master’s degree in mathematical statistics at the University of Queensland, she took off to the City of Lights. She qualified for a PhD in geostatistics after the distance-weighted average had shed its variance. Stripping variances off distance-weighted averages AKA kriged estimates has stood the test of time. Nobody ever thought about counting degrees of freedom on Matheron’s watch.

Professor Dr Roussos Dimitrakopoulos was also a graduate at the University of Queensland in Australia. Dr RD dismissed degrees of freedom but got into stringing Markov chains at McGill University in Canada. He did so because he does not know how to derive unbiased confidence limits for metal contents and grades of mineral inventories.

Professor Dr Michel David must have been pleased that mine planners were to blame for over-smoothed estimates. But he was not at all pleased that my talk about Sampling in Exploration-Theory and Practice was a first at PDAC’s meeting on March 23, 1991. He took a seat opposite my lectern and didn’t  pose a single question! Neither did other geostatistocrats!

In 1992 I visited BHP’s mining operations in Australia. The problem was BHP’s assay laboratory got significantly lower grades than its mine planners had been predicting. For crying out loud! Surely, investors should get unbiased confidence limits for metal contents and grades of mineral inventories!

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