Ripping: Complete Technical Guide

Ripping is the quarry art of breaking rock without blasting it: a single hardened steel tooth, pulled through the ground by a crawler tractor, splits the rock along its bedding planes, its joints and its natural weakness, and the bank falls apart into loadable fragments: where the formation is weathered, bedded or well jointed, ripping replaces the drill rig, the explosive magazine and the blast permit, and the cement quarry produces its daily tonnage to the sound of a diesel engine instead of the sound of a shock wave: the method handles millions of tonnes of limestone, marl and clay worldwide every year, and every cement engineer who plans a new pit or operates an existing one must know when ripping works, how fast it works, and what it costs: this article covers the subject completely: the definitions, the physics, the rippability assessment, the machines, the operating technique, the economics with worked examples and the troubleshooting of the ripping operation in the cement raw-material quarry.

The document behind this article is part of the Complete Cement Technical Package (931 files including handbooks, operating procedures, Excel tools and training presentations: $249.99 one-time payment: instant download through PayPal): the quarry-practice document of the package carries the machine data sheets, the rippability charts, the productivity calculators and the cost-comparison worksheets between the ripping and the blasting route: this article walks that document section by section: the engineer who reads it can then open the ripper estimator of the package and size a ripping job of his own quarry in a working afternoon.

The one central judgment the reader should take away: ripping is a decision, not a habit: the same rock that rips beautifully at the top of the mountain blocks the dozer at its base, and the quarry engineer must know where the economic line sits before the tractor is ordered: the seismic velocities, the rippability classes, the machine weights, the production curves and the cost per tonne of this article give that decision its numbers: read the definitions first, the physics second and the practice last: the worked examples show how the figures combine on a real rock formation.

1. The Position of Ripping in the Quarry Production Chain

The cement plant consumes roughly 1.2 to 1.8 tonnes of raw material for every tonne of clinker produced, and every tonne must move from the solid ground to the crusher feed: the production chain is the loosening, the loading, the hauling and the crushing: ripping occupies the loosening stage, and its position within the chain decides its value:

• The loosening role: ripping performs the loosening by mechanical force alone, where drilling and blasting perform it with explosives: the choice is either route at the same point of the chain: drill, or rip, and then the excavator picks up the loose material:
• The input to loading: the ripping product is a loose, broken bank at the foot of the bench: the hydraulic excavator or the wheel loader fills the haulers directly, with fragment sizes of 30 to 60 centimetres typical, which the primary crusher accepts without secondary reduction:
• The interface with the crusher: the crusher receives the ripped stone without the blockages that slabby blasted rock occasionally causes, because the ripper follows the natural fracture planes and produces manageable fragments: the plant stops less often and the quarry advance becomes a continuous flow:
• The weather tolerance: ripping runs in rain, in mud and in snow where the blasting must wait: the crawler traction and the exposed face keep the production moving: the quarry calendar gains the days that the explosive route would have lost:
• The boundary with blasting: the geologist marks the rippable boundary within the formation: above the line the tractor works alone, below it the drill rig and the explosives take over: the two zones meet at the point where the ripping cost per tonne equals the blasting cost per tonne:

The chain decides the method: the quarry whose limestone is soft, jointed or weathered can rip the whole bank and never store an explosive; the quarry whose stone is massive and tight must blast and rarely starts the ripper: the typical cement quarry runs a mix, ripping the softer beds at the top of the formation and blasting the harder benches below, while the raw-mix chemist blends the two products: within this chain ripping is not a helper operation: it is a primary production system that deserves its own engineering, its own measurement and its own cost account.

2. The Definitions: What Ripping Is, and What It Is Not

The document fixes the vocabulary at the start, because the quarry trade uses the words loosely and the confusion costs money:

• Ripping: the mechanical fracture of rock in place by a toothed tool, the ripper, drawn through the ground by a self-propelled crawler tractor: no percussion, no explosion and no water jet: only the steady pull of the machine at full engine power converted into the shear of the ground mass:
• The ripper: the heavy steel shank carried on the rear of the tractor, terminating in a replaceable tooth tip, with the shank angle adjusted hydraulically: the single-shank machines work the hardest ground, the multi-shank machines spread the load over the softer materials:
• The traction: the first mover of the process: the crawler tracks convert the engine power into drawbar pull, and the machine weight presses the tooth into the rock: without traction there is no ripping, which is why the crawler is the universal ripping carrier:
• What ripping is not: it is not a plough furrow in soil, not scraping, and not the percussive work of a hydraulic hammer: the hammer delivers impact energy at high frequency; the ripper delivers quasi-static force at walking speed: different physics, different wear, different cost:
• The rippable rock: any rock that yields to the weight and the pull of a practical tractor: weathered limestone, shale, siltstone, heavily jointed sandstone, marl and clay all rip routinely, while fresh granite, massive quartzite and tight fresh basalt do not:

The definitions draw the boundary in the ground: the world of ripping is the rock that geology has already weakened, by bedding, by jointing, by weathering or by the stress relief of the geological past: the world of blasting is the rock that geology left whole and strong: the engineer holds these two classes in mind and the entire decision procedure of the document follows from the classification: most cement raw materials, fortunately for the industry, live on the rippable side of the line.

3. The Physics of the Ripping Tooth: Tool and Rock

The ripper is a tool, and its work is the interplay of penetration, pull and fracture: the document reduces the operation to five balances that the engineer can hold in the head during a site visit:

• The penetration: the tooth must enter the ground first: the tractor weight carried over the tail presses the tip into the rock, and the tip sharpness, the rake angle and the shank angle decide whether the tip chisels in or skates over the surface: working depths of 30 to 90 centimetres are typical in cement quarries:
• The pull force: the tractor develops a drawbar force of the order of 10 to 30 percent of its operating weight in ripping service: a D10-class machine pulls 130 to 180 tonnes, a D11-class up to about 250 tonnes: the force reaches the rock through the shank lever arm behind the machine:
• The fracture mechanism: the tip splits the rock preferentially along the planes that already exist, the bedding, the joints and the faults: where the rock lacks planes, the fracture is shear under the combined tip pressure and pull: the useful work is the force multiplied by the travel distance, converted into new crack surface:
• The depth of influence: the forces spread downward and sideways from the tip, so a pass cracks a slab wider than the tooth itself: the spacing between adjacent passes must be smaller than the effective depth, otherwise untouched ridges remain between the furrows:
• The tip-rock interface: the abrasive wear of the tip is the life cost of ripping: the wear rate follows the quartz content of the rock and the tip grade: carbide-tipped and resharpened steel tips are the two families, and the change intervals are recorded to keep the penetration at its design value:

The physics is that of a moving wedge: the wedge loaded inside the ground, the rock cracking along its weakness, the tractor winning the fight by weight and power: ripping is roughly eighty percent pulling and twenty percent positioning, so the machine that can maintain the required drawbar pull at the chosen depth sets the production rate: the engineer checks the engine power, the weight and the gearing of the candidate tractor against the measured ground before the first pass.

4. The Rippability Assessment: Judging the Ground

No ripper is ordered before the site has been judged, and the document sets out the complete field classification procedure from the geological map to the seismic survey:

• The seismic velocity method: the primary rippability number is the compressional wave velocity of the formation, measured by a shallow refraction survey: the velocity bands are compared with the rippability charts of the tractor manufacturers: velocities below 600 m/s rip easily, velocities above 3000 m/s are almost always the blasting zone:
• The geological factors: rock type, degree of weathering, bedding thickness, joint spacing and joint orientation: a limestone at 1800 m/s with closely spaced joints rips quickly, while the same rock at the same velocity without the joints does not: geology supplies the exceptions to every seismic rule:
• The observation tests: the direct checks: the penetration of the excavator bucket, the seismic shot, and the full ripping trial over a hundred metres at the true working condition: the trial result is the final truth, because it includes the machine, the operator and the weather:
• The rippability classes: the conventional classification from class 1 (very soft) to class 5 (very hard), with estimated hourly production rates on each class: the class system is the common language between the geologist, the planner and the equipment supplier:
• The estimate tools: the 24-channel refraction recorder, the geophone string, the sledge hammer or small explosive source, the joint map drawn by the geologist: the document carries a complete worked survey of a real formation with the velocities and the verdicts in one table:

The rippability analysis is made once at the start of the operation and reviewed every time the bench changes: the survey costs a fraction of the wrong decision: a tractor that falls short of its task loses shifts, tips and fuel; one that is oversized carries needless capital and fuel cost: the document calls this step the geological due diligence of the quarry, and the serious quarry engineer treats it as a routine survey, like the topography, and never opens a new bench without it: the typical velocity-to-method table of the package appears below.

5. The Equipment: Tractors, Rippers and Tip Steel

The ripping equipment inventory is small but the selection parameters are precise: weight, power and tooling, and the document tabulates the major machine classes:

• The ripper frame types: the parallelogram ripper holds a constant shank angle through the penetration stroke, the radial ripper swings the tip through an arc and adds a wedge action: the parallelogram is the modern standard for hard-rock service:
• The machine classes: the industry standard classes from the 250 kW machines at 40 to 50 tonnes up to the 600 kW machines at 90 to 120 tonnes: the class is chosen from the seismic velocity and the required depth, and the charts of the suppliers map machine to rippable velocity directly:
• The tips and shanks: the carbide-tipped conical tips for the abrasive ground, the resharpened steel for the softer formations: the shank rake angles of 40 to 65 degrees balance penetration against pull: the tip change at the right interval keeps the production curve flat:
• The supporting fleet: the water wagon for dust control, the dozer for windrow spreading and bench cleanup, the grader for the access roads, the tool service truck with the tip rack and the welding set: ripping consumes the support fleet as much as the tractor itself:
• The ripper-tractor fit: the ripper must be matched to the tractor rear frame, the hydraulic circuits and the cooling capacity: the package data sheets list the approved ripper combinations, the pin diameters and the reach dimensions: the match is the warranty boundary of the ripping life:

The selection principle of the equipment chapter is a balance of three parameters that must be true at the same time: enough weight to penetrate, enough power to pull, and enough reach to work the bench height: the machine that is too light digs its own nose into the ground, the machine that is too heavy pays for steel it never uses: the equipment table of the package ends with an index of machines with weights, powers and the recommended rippability velocities, so the comparison between the suppliers is made on one page.

6. The Operating Technique: Direction, Pattern and Rhythm

The machine is nothing without the method, and the ripping method is the engine of the production rate: the document teaches five operating rules that separate the professional crews from the amateurs:

• The direction of the passes: the rips run along the dip of the bedding planes and in the direction of the weakest joint family, never across it: the tooth then works with the rock’s own weakness instead of against a fresh surface, and the production difference between the wrong direction and the right one can be a factor of two:
• The depth and the speed: the machine works at 65 to 80 percent of its maximum depth capability, at ground speeds of 1 to 3 km/h: the low range is for the deep ripping of hard rock, the higher range for the shallow passes in soft material: the operator trades speed against depth continuously:
• The pass spacing: single passes spaced at 1 to 3 metres, with cross ripping at 60 to 90 degrees across the first set wherever the geometry allows: the cross ripping attacks the slabs from two sides and breaks what the single pass leaves standing:
• The windrow management: the loosened material piles at the end of the pass: the windrow is spread by the dozer blade of the same machine or by the supporting dozer, so the tractor reverses clear of its own heap and the next pass starts on clean ground: the rhythm of the windrow is the rhythm of the shift:
• The bench sequence: the common cement-quarry sequence rips the bench from the top downward in slices, ripping the full width before the loader strips the loose: the face stays stable, the loader works on flat ground, and the next bench slice is exposed and dry for the following week:

The technique chapter of the document presents the pass patterns as drawings with the turn symbols and the spacing notes, and provides the operator sheet that the shift foreman fills in: the combination of direction, depth, spacing and windrow rhythm determines the hourly tonnes more than any other factor: the same tractor can produce 600 tonnes in one formation and 150 in the next, and the difference is mostly technique, not machine.

7. The Seismic Refraction Survey: Measuring the Ground

The quantitative rippability assessment begins with the seismic measurement, and the document covers the whole field practice from the layout to the interpretation:

• The principle: a seismic source, the hammer blow or the small charge, generates compression waves in the ground: geophones at increasing offsets record the first arrivals, and the layer velocities are derived from the slopes of the arrival time against the distance curve:
• The field equipment: the 24-channel recorder, the geophones, the trigger cable and the sledge hammer of 8 to 16 kilograms, or the small explosive source where the depth requires it: a two-man crew lines 300 to 800 metres in a day at geophone spacing of 15 to 25 metres:
• The interpretation: the velocity model of two or three layers under the line, the weathered zone, the fractured zone and the fresh rock: the velocity values are compared with the machine rippability charts, and the boundary of the zone is drawn on the quarry plan:
• The judgement: the seismic velocity is the geometry and the judgement: one velocity reading in a canyon of the same limestone can change with the water content and the altitude, so the interpretation is a professional act, not a mechanical one: where the reading and the geology disagree, the trial rip settles the dispute:
• The routine use: most cement plants shoot the survey once when the quarry plan is drawn, and again when the mining passes into a new geological zone: the updated map of rippable and blastable zones is then the base layer of the excavation plan for the next five years:

The seismic method supplies the numbers that replace the guess: the rippability chart of the machine manufacturers, with the machine class and the seismic velocity on the axes, is the standard judging instrument, and the document completes the chapter with a fully worked example: the field table of arrival times, the plotted curves, the computed layer velocities and two pages of interpretation: the skill of the interpretation is earned on examples, and the examples of the package take the reader through the whole exercise exactly as the crew would do it in the quarry.

8. The Ripper in the Cement Raw-Material Quarry

The ripping practice of the cement industry has its own character because the raw materials are specific, and the document devotes a chapter to the materials of the trade:

• The limestone: the primary carbonate rock of Portland cement: the typical plant works benches of 5 to 25 metres: weathered, bedded and jointed limestones are natural ripping materials, while uniform dense limestone does not rip and keeps the blasting route: the arcilite quality and the petrography decide the method:
• The marl: the ideal ripping material of the cement industry: argillaceous, soft, layered, and rips at high rates: marl benches routinely produce 500 to 1500 tonnes per hour with a medium class machine and the excavator loads directly without secondary breaking: in many deposits the marl and the limestone are ripped in the same production campaign:
• The clay and the overburden: the cap of the deposit, the clay, the gravel, the soft and partially hardened layers: the multi-shank ripper and the dozer plow the cover without tip breakage: every cement quarry handles its own top layer before the harder stone is touched:
• The chalk: a very soft carbonate that rips in every season but binds the tools in wet periods: the chalk clings to the shank and the tracks, and the washing and the hammering may cost as much as the ripping itself: the wet-chalk practice is its own operating chapter:
• The mix and the chemistry: the quarry plan and the raw-mix plan are one plan: the ripped and the blasted zones are blended by the crusher feed program, and the geologist’s bench sections are the basis of both: the ripper does not care about the chemistry, but the plant does, and the bench plan must feed both:

The cement quarry is the ideal ripping ground of the whole mining industry: many cement raw deposits are bedded sediments that geology has prepared for the ripper: the document’s material tables give the rip rates, the tip lives and the machine classes for limestone, marl, clay and chalk, and the quarry engineer of the cement plant can apply the table directly to his own benches: the ripping route is the reason many cement quarries operate a full lifetime without firing a single blast.

9. The Economics of Ripping: Cost per Tonne, Worked Example

The decision between ripping and blasting is finally an economic one, and the document gives the complete cost model that the cement plant applies to its own figures:

• The cost elements of ripping: the owning cost of the tractor (depreciation, interest and insurance), the operating cost (fuel, lubricants, filters, tips, shanks and tracks), the operator wage and the supervision: the total is divided by the tonnes produced to obtain the cost per tonne:
• The cost elements of blasting: the drilling cost, the explosives and accessories, the blasting service, the permit and insurance, the blast-related plant stops, the secondary breaking of oversize and the crusher stoppages: many plants forget the secondary costs, which is exactly where ripping wins:
• The comparison basis: both routes are compared at the crusher feed, not at the quarry face: the fragmentation quality, the oversize rate and the crusher utilization are part of the comparison: the ripping route usually delivers a better crushing feed than blasting on the same material:
• The sensitivity factors: the ripping cost per tonne rises steeply as the rock becomes harder, while the blasting cost is comparatively flat: the crossover point is the economic boundary, and it moves with the fuel price, the tip price and the drill productivity: the document’s worksheet recomputes the boundary in minutes:
• The ownership arithmetic: the yearly operating hours of the ripping tractor are the decisive assumption: a tractor working 2500 hours per year carries a lower cost per hour than the same tractor working 1200 hours: the quarry must give the machine a full program or the ripping route looks worse than it is:

The worked example of the document: a cement quarry rips 1.8 million tonnes of marl and weathered limestone per year: the tractor is a medium-heavy class machine at an all-in cost of $185 per working hour including the operator, fuel, maintenance and the prorated purchase: the measured production is 380 tonnes per hour on the bench: the cost per tonne is 185 divided by 380, equal to 0.49 dollars per tonne: the comparative drill-and-blast route on the neighbouring bench costs 0.65 dollars per tonne all-in including the secondary breaking: the saving of the ripping route is 0.16 dollars per tonne, or 288,000 dollars per year on the full production: the example explains in one paragraph why the management of that quarry never considered the explosives for the marl zone again: the numbers of the same worksheet are reproduced in Table 3 below.

10. The Production Estimate: The Hourly Tonnage Worked Example

The production rate of a ripping tractor is estimated from the geometry of the pass, and the document teaches the method with numbers:

• The formula: the hourly production in cubic metres equals the working speed in metres per hour multiplied by the average depth of the rip in metres multiplied by the effective width loosened per pass in metres: the effective width is the pass spacing plus the crack spread, often taken as the spacing itself in the first estimate:
• The data of the example: a tractor rips at 1.8 km/h at an average depth of 0.6 metres with a pass spacing of 2.0 metres in a jointed marl: the geometric production is 1800 times 0.6 times 2.0, equal to 2160 cubic metres per hour of swept volume:
• The efficiency factors: the ripping is not continuous: the turns, the windrow spreading and the pauses consume time: the operating efficiency of a well-managed ripping shift is 60 to 75 percent, and the loosening factor, the swell, of the ripped material is 1.15 to 1.35 depending on the rock:
• The result: the effective production is 2160 cubic metres per hour multiplied by 0.70 efficiency, equal to 1510 bank cubic metres per hour: at a rock density of 2.2 tonnes per bank cubic metre the production becomes about 3300 tonnes per hour, which is beyond the machine class of the example: the estimator must then reduce the spacing or the depth until the machine pulls the load, and the iteration is the actual skill:
• The confirmation: the computed number is always compared with the tractor manufacturer’s rippability chart and with the observed trial production: the three numbers, the geometric estimate, the chart estimate and the trial, converge on the figure that the shift plan uses: the document’s Excel calculator performs the iteration in seconds:

The production estimate is a discipline, not a guess: the same exercise run with the depth of 0.4 metres instead of 0.6 reduces the swept volume by one third, and with the efficiency of 50 percent the tonnage nearly halves: the planner who writes the shift target from the worked geometry and the measured efficiency runs a quarry that meets its contract, while the planner who guesses feeds the crusher by luck: the document closes the chapter with the standard estimate sheet that the quarry engineer fills for every bench change.

11. The Maintenance and the Wear Life of the Ripper

The ripper works in the most abrasive environment of the quarry, and the maintenance discipline decides the hourly cost more than the purchase price:

• The tip steel: the highest wear item: the carbide tips are changed by the hour count on the abrasive ground, the resharpened steel tips by the shift: the document’s tip-life tables give the expected life in hours against the rock type and the machine class, and the worn tip is replaced before the penetration drops, because a dull tip costs more fuel than the tip saves:
• The shank and the frame: the shank bends and the frame cracks under the impact of the hard pulls: the daily visual inspection covers the welds, the pin bores and the shank straightness: the cracked frame is repaired by the qualified welder with the preheating procedure, never by the field quick weld alone:
• The tracks and the undercarriage: the ripping duty is the severest track duty known: the shoes, the pins and the bushings wear fast and the track adjustment is checked weekly: the undercarriage is the second largest cost block of the machine after the fuel, and its life is protected by the clean working area and the correct tension:
• The engine and the cooling: the ripping loads the engine at full power for hours: the radiator, the hydraulic oil coolers and the pre-cleaners are cleaned on the shift schedule, and the engine oil analysis is performed monthly on the abrasive dust: the overheated machine loses power exactly when the pull is needed most:
• The records: the ripping cost per hour is meaningless without the records: the package supplies the maintenance log sheets: the tip changes, the fuel, the delays, the repair hours and the production of every shift: the cost per tonne of the previous section is only as good as the log behind it:

The wear life of the ripping fleet is managed with the same discipline as the mill relining: the tip-change interval, the undercarriage rebuild interval and the track adjustment are all scheduled, and the shutdown is planned into the maintenance calendar instead of being forced by the failure: the quarry that changes the tip at the hour mark gets 15 to 20 percent more production than the quarry that changes it after the penetration loss is noticed: the maintenance chapter of the document provides the complete inspection checklists in the exact order of the daily, weekly and monthly service.

12. The Troubleshooting of the Ripping Operation

The symptoms of a poor ripping operation are visible in the benches and in the cost account, and the document’s troubleshooting section pairs every symptom with its causes and the check sequence:

• The tractor cannot pull the pass: the pass too deep for the machine class, the shank angle set for penetration instead of pull, the tip dull, the tracks slipping on the wet ground, the engine overheated: the checks in order: tip condition, shank angle, depth reduction, track condition, then the ground moisture:
• The tooth will not penetrate: the tip is blunt or wrong-shaped for the ground, the machine is too light over the tail, the ripper frame is raised and vibrating instead of pressing, the rock is beyond the rippable class: the trial ripping on the spot answers whether the class changed, and the tip change answers the rest:
• The production drops during the shift: the tip wear accumulating through the shift, the fuel tank and the filters, the operator fatigue with the falling rhythm, the windrows not cleared: the instrument reading of the depth and the speed shows exactly where the pass turns shallow:
• The tracks slip: the wet clay ground, the muddy bench, the insufficient track tension, the steep working angle: the remedy is the drainage of the bench, the gravel cover of the working lane, the wider shoes for the soft ground: the track slip burns fuel and produces nothing:
• The rock comes out slabby and oversized: the pass spacing is too wide for the depth, the direction runs across the joints, the cross ripping is missing: the pattern table of the document gives the spacing-depth ratio, and the cross pass breaks the residual slabs:

The troubleshooting table of the document lists the twenty most common symptoms with the first, second and third cause: the experienced crew checks the leading cause in thirty seconds: most ripping problems are tip steel, direction and rhythm, not the machine: the quarry that keeps the diagnosis list beside the operator finds that the expensive repair history of the ripper is mostly the history of the neglected inspection.

13. The Safety and the Environment of the Ripping Operation

Ripping removes the largest safety hazard of the quarry, the blast, and introduces its own smaller family of risks, and the document covers both sides:

• The blast-free advantage: no fly rock, no ground vibration, no unexploded charges, no blast exclusion zone, no night security around the magazine: many European cement quarries operate in populated districts precisely because the blasting was replaced by the ripping: the social license of the plant improves with the method:
• The operator hazards: the machine tips when the bench edge collapses, the flying chips strike the cab glass, the tool change injures the hands, the vibration fatigues the operator: the rules: the bench edges marked, the cab with the armored glass, the gloves and the tongs at the tip change, the rotation between operators:
• The dust control: the ripping is dry in the summer and dusty: the water wagon follows the tractor in the dry season, the working lanes are wet, the operator’s cabin filter is serviced, and the silicosis monitoring of the crew is the plant’s obligation: the dust of the ripped face is equal to the blast cloud problem:
• The noise: the continuous diesel noise at the working distance is lower than the blast but continuous: the plant measures the site boundary noise and schedules the ripping at the permitted hours, the same discipline as the mill and the crusher:
• The environmental monitoring: the vibration of the ripping is negligible against the blasting, the water run-off of the ripped benches drains normally, and the rehabilitation of the quarry follows the same plan after either method: the environmental inspector at the cement quarry with the ripping operation finds little to object to:

The safety chapter of the document ends with the risk assessment example of a complete ripping site, the hazards listed, the risk rating before and after the controls, and the responsible persons named: the quarry that keeps the assessment current is the quarry that keeps its crew whole: the ripping operation, freed of the explosive and its rules, concentrates the safety effort on the machines, the fatigue and the dust, and the document treats those three with the same rigor that the blasting regulations carry elsewhere.

14. Conclusion

Ripping is the quiet engine of the cement raw-material chain: the single tooth drawn through the ground breaks what the bedded sediment geology has prepared, and the cement quarry gains the production without the drill patterns, the magazines and the blast permits: the physics of the wedge, the assessment of the seismic velocity, the selection of the machine class, the discipline of the technique, the economics of the cost per tonne and the maintenance of the tip steel are the complete science that this document presents: the reader who has followed the worked examples can now judge any bench: measure it, estimate it, and cost it: the ripping decision of the cement quarry is one of the rare engineering decisions where the simpler machine does the job: this article has shown the complete method, and the package document carries the tables, the charts and the calculators that put the method to work in the plant.

The Complete Cement Technical Package includes this complete ripping and quarry-practice document with the rippability charts, the seismic interpretation examples, the production calculators and the cost-comparison worksheets: the one-time $249.99, the instant download, the lifelong reference: the quarry engineer who follows the package becomes the engineer who decides the excavation route on numbers instead of habit: the same discipline applies to every other station of the cement plant, from the quarry bench to the finish grinding silo.

The Frequently Asked Questions

How do I know if my limestone rips or needs blasting?

Order a shallow seismic refraction survey over the proposed bench and compare the measured compressional velocities with the rippability chart of the machine manufacturers: under about 1500 m/s the medium classes rip, between 1500 and 2500 the heavy classes rip at the practical limit, above 2500 the blasting is usually cheaper: then run the hundred-metre trial rip with the candidate machine: the trial verdict settles the case the survey leaves open.

What is the real cost difference between ripping and blasting?

On the materials that rip, the all-in cost of ripping including the machine, the operator, the fuel and the tip steel commonly lands between 0.3 and 0.8 dollars per tonne, versus 0.5 to 1.0 dollars per tonne for the complete drill-and-blast route including the secondary breaking and the crusher delays: the worked example of the article showed 0.52 versus 0.65 dollars per tonne on a marl-limestone mix: the difference of every plant is its own, and the cost worksheet of the package recomputes it with the local figures.

Why does my ripper not wanting deeper than 30 cm?

The depth is the product of the weight on the tip, the shank angle and the tip sharpness: install the sharpest tips of the right shape, set the rake angle to the penetration range of 55 to 65 degrees, and check that the ripper frame carries the full machine weight on the tail: if the penetration still will not go, the rock is above the rippable class or the machine is one class below the job: the manufacturer’s chart answers which.

Does ripping damage the crusher feed quality?

On the contrary: ripping follows the natural fracture planes and produces cleaner fragments with fewer slop plates than blasting on the same rock, the oversize rate is lower and the crusher utilization is usually a few points higher: the comparison must be made at the crusher feed and the two routes on the same material, and the ripping route regularly wins both the cost and the utilization.

Can the ripping replace blasting completely in my cement quarry?

Only where the whole deposit lies in the rippable class: many deposits have a hard massive zone below the weathered beds, and the practical plan is the mixed operation, the ripper on the soft upper beds and the drill and the blast on the massive lower zone, with the two products blended in the raw-mix plan: the boundary is moved annually by the survey: the crushing and the silica of the deposit choose the method.

This file is part of the Complete Cement Technical Package (931 files) available from cementequipment.org. Respective rights holders; library copy for the licensed single user.