Abstract: Process for the production of sodium chlorate by the electrolysis of sodium chloride contaminated with sodium sulphate wherein the sulphate concentration in the system is kept below a pre-selected level. A portion of the mother liquor remaining after crystallizing out some of the sodium chlorate product is selectively further cooled to effect crystallization of some of the sodium sulphate present in the liquor. An acceptable "steady-state" concentration of sulphate ion is established which prevents the deleterious excess sulphate ion build-up in the electrolytic system.

Abstract: A method of smooth wall rock blasting is provided in which an alignment of boreholes for explosive charging is drilled into rock and a single, smaller diameter empty borehole is drilled close and parallel to, and on each side of each charged borehole. Upon detonation of the charged boreholes, the rock is cracked smoothly along the plane coincident with the axes of the holes. The method reduces drilling costs to a minimum and provides improved results over the previous pre-shearing and other known methods.

Abstract: A packaged booster charge is provided which is sensitive to initiation by blasting cap yet which contains no self-explosive ingredient. The composition of the booster comprises a low melting point nitrate salt or salt mixture having dissolved or finely dispersed therein an acetylenic substance and void containing material. The booster is safe and economic to manufacture and sufficiently powerful to initiate insensitive blasting agents.

Abstract: A thermoplastic heavy duty shipping bag having walls formed of cross-laminated outer plies of uni-axially oriented polyethylene and inner walls of low density polyethylene, heat sealed thereto. The bag provides improved puncture and snag resistance.

Abstract: A cold-drawn unbalanced biaxially oriented linear low density polyethylene film having a transverse direction draw ratio selected from greater than 1 to less than 3 and a machine direction draw ratio of less than 6 but greater than the transverse direction draw ratio. The film has enhanced tensile and puncture resistance while maintaining acceptable tear properties and is used for shipping sacks.

Abstract: A shipping sack having walls formed of uni-axially oriented linear low density polyethylene film wherein said film is produced by blowing and cold drawing said polyethylene at a draw ratio to blow ratio of greater than 1:1, preferably, between 2:1 and 5:1. The sack can be used as a tubular shipping sack for bulky, lightweight material or, if optionally provided with a double inner film of low density polyethylene, as a heavy duty sack. The sacks have improved physical properties.

Abstract: Process and apparatus for the generation of sulphur trioxide from oleum using microwave energy for use in the sulphonation and nitration of organic compounds and the fortification of oleum. The process provides improved control of production and concentration of the sulphur trioxide produced and comprises subjecting sulphur trioxide-rich oleum feed to microwave energy for a sufficient period of time to produce sulphur trioxide vapour and spent oleum; isolating said sulphur trioxide vapour and collecting said spent oleum.

Abstract: A thermoplastic shipping bag having a thermoplastic inner ply comprising a mesh which permits the packaging of finely powdered materials without releasing unacceptable levels of powders to the atmosphere during or after filling and without requiring significant modification to packaging systems used to fill and process multi-wall paper shipping bags.

Abstract: Process and apparatus for the generation of sulphur dioxide vapor from contaminated liquid sulphur dioxide. The process allows of utilization of contaminated liquid sulphur dioxide and comprises subjecting liquid sulphur dioxide feed to microwave energy for a sufficient period of time to produce sulphur dioxide vapor, collecting said vapor and removing resultant contaminated liquid sulphur dioxide, if any.

Abstract: This invention relates to a process for the production of concentrated sulphuric acid from waste sulphuric acid which comprises subjecting said waste acid to microwave energy for a sufficient period of time to effect production of water vapor, whereby said waste acid is concentrated to a desired degree; removing said water vapor; and collecting said concentrated acid.

Abstract: A continuous process for the generation of sulphur trioxide from oleum suitable for use in the sulphonation of organic compounds which comprises continuously introducing oleum feed to a sulphur trioxide desorption tower; continuously introducing a recycled dry feed air stream to said desorption tower, whereby a gaseous mixture of sulphur trioxide in air is produced; collecting spent oleum from said desorption tower; introducing said gaseous mixture to a sulphonation reactor; and recycling spent gaseous mixture from said reactor to said desorption tower as said feed air stream. The process offers reduced environmental pollution and operating costs.

Abstract: An absorption tower for absorbing sulphur trioxide in sulphuric acid having distinct upper and lower packed absorption zones wherein substantially all of the sulphur trioxide is absorbed by the sulphuric acid in the lower zone, while in the upper zone the depleted gas stream is significantly cooled. The two zones receive feed acids of different temperatures and different acid irrigation rates. The tower allows of improved energy recovery while providing for environmentally acceptable emission standards.

Abstract: An apparatus and method is provided for measuring the continuity and resistance of electric circuits, particularly electric wire circuits used in blasting, in the presence of spurious voltages due to galvanic currents. A constant current from a cell is passed through the electric circuit to be tested and through a reference resistor where the voltages are measured to derive the resistance of the circuit. The measured voltages are sensed with a converter converted to a resistance measurement and displayed. The presence of spurious voltages is compensated for by connecting a galvanic current storage capacitor in the circuit, passing a reference current through the reference resistor and the circuit and comparing the voltage across the reference resistor with the voltage across the circuit and storage capacitor to derive a resistance reading. The reading is converted to a digital display.

Abstract: A combined sulphur burning furnace and water-cooled boiler arrangement for producing a cooled, gaseous sulphur dioxide-air mixture in which the furnace is located below the boiler tubes arrangement in a vertical, cylindrical shell. The hot gases produced in the furnace exit axially into an upper chamber defined by the water-tube arrangement and pass through the cooling water-tube arrangement in radial outward flow to an outer chamber provided with cold-side by-pass control means and then exit the shell. The apparatus provides for savings in ducting, foundations, piping and the like; and permits more efficient sulphur burning and cooling.

Abstract: In a system using the double absorption process for sulphuric acid manufacture, a single acid circulation system and a single cooler are employed. Acid from the exit of the air drying tower and final absorber tower are mixed in a common reservoir, while acid from intermediate absorber tower is discharged to a separate reservoir. Acid from the common reservoir is split between the intermediate and final absorber towers and product line. Acid from the separate reservoir is cooled and split between the drying tower and intermediate absorber tower. The circulation arrangement reduces the cooling to one relatively high temperature location and simplifies acid strength and level control. Only half of the bulk of the circulating acid has to be cooled and the effect of seasonal fluctuating temperatures in the drying tower is minimized.

Abstract: An anodic protection system particularly useful in heat exchangers for cooling sulphuric acid, in which the cathode projects through both ends of the heat exchanger and a negative potential is applied to both ends of the cathode. The potentials are controlled to ensure that the hot and cool ends of the heat exchanger metal (tubes and shell) which ends have different potential requirements for remaining in the passive range, both remain within their respective passive ranges.

Abstract: Process for the production of liquid sulphur dioxide in a sulphur dioxide facility forming part of a sulphuric acid plant wherein a portion of the sulphur dioxide produced in a sulphur burning furnace is directed to a sulphur dioxide liquefaction means and the resultant tail gas is recycled to the furnace. Relatively high sulphur dioxide concentrations are maintained in all parts of the sulphur dioxide production cycle allowing higher strength sulphur dioxide gases to be generated without overheating the furnace and also lower power requirements in the sulphur dioxide liquefaction step.

Abstract: A thermoplastic heavy duty shipping bag having walls formed of cross-laminated outer plies of uni-axially oriented polyethylene and inner walls of low density polyethylene, heat sealed thereto. The bag provides improved puncture and snag resistance.

Abstract: A process for producing concentrated sulphuric acid from a hot gas stream comprising water and sulphur trioxide which process comprises feeding a first portion of said gas stream through a first sulphur trioxide absorption zone and a second portion through a second sulphur trioxide absorption zone; feeding a recycled sulphuric acid stream to said first sulphur trioxide absorption zone whereby substantially all of the sulphur trioxide and sulphuric acid are removed from said first portion of said gas stream to produce an enlarged sulphuric acid stream; recycling a first portion of said enlarged sulphuric acid stream through said first sulphur trioxide absorption zone; feeding a second portion of said enlarged sulphuric acid stream to said second sulphur trioxide absorption zone; and collecting sulphuric acid product from said second sulphur trioxide absorption zone; wherein the ratio of gases to sulphuric acid in said second sulphur trioxide absorption zone is such that the sulphuric acid product leaving said

Abstract: Apparatus and process for the manufacture of sulphuric acid by the contact process of the type comprising at least one gas-concentrated sulphuric acid contacting unit and a sulphuric acid heat exchanger characterized in that the contacting unit and/or heat exchanger is formed of high silicon content austenitic steel. The steel is also of use in sulphuric acid concentrators. Reduced corrosion rates are provided.