Three methods to process Trinidad natural asphalt

Abstract

The world's natural asphalts are thermoplastic and coalescent in nature. After removing its water content, the resulting refined asphalts flow, coalesce, its mineral matters sediment when used in blends, and therefore could only be used with specialized road-paving equipment. Three methods are presented here to solve these problems. Method One gives a new way of packaging the natural and refined asphalts in pellet-form. Method Two uses water surface to stop the pellets of natural or refined asphalts from coalescing. Method Three uses water to blend the natural or refined asphalts, producing powders and pellets which do not flow or coalesce. In all methods, the processed asphalts are packaged for use on conventional road-paving equipment, without loss in performance when compared with the refined asphalts.

Claims

1. An asphaltic road paving product made by the process comprising: obtaining Trinidad natural asphalt or refined Trinidad lake asphalt, disposing said asphalt into a vessel and mixing said asphalt with 2-3% by weight of water to form discrete pellets having a size between 1-10 mm; stabilizing said discrete pellets by removing water from said discrete pellets by subjecting said discrete pellets to air at a temperature between 50-100 C. for 3-5 minutes to minimize the loss of maltene-content in the asphalt resulting in providing a non-flowing and non-coalescing pellets which contain no additives.

2. An asphaltic road paving product made by the process comprising: obtaining Trinidad natural asphalt or refined Trinidad lake asphalt, disposing said asphalt into a vessel and mixing said asphalt with 2-3% by weight of water to form discrete powders having a size between 20 microns to 1 mm; stabilizing said discrete pellets by removing water from said discrete pellets by subjecting said discrete powders to air at a temperature between 40-60 C. for 1-2 minutes to minimize the loss of maltene-content in the asphalt resulting in providing a non-flowing and non-coalescing powders which contain no additives.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) 1. The Three Methods.

(2) (a) Method One: Packaging only.

(3) Section 4 Item 2(a) shows the flowchart of how these processed asphalts are produced and used.

(4) The process is detailed in Section 4 Item 2 (a).

(5) In this Option One, the natural asphalt, with its water content, is crushed to discrete elements.

(6) In this Option Two, after the refined asphalt has been produced from the natural asphalts (Section 3 Item 7), the refined asphalt is then crushed to discrete elements.

(7) The discrete elements in Options One and Two must be so small enough so that the elements could be transported via the conveyor belts directly to the drum/pug-mill on conventional road-paving equipment. These sizes could be about 0.5 kg or larger.

(8) These pellets are then packaged in plastic bags.

(9) No heat is used in the process, and there is no temperature increase during the processing.

(10) No additive is used, not even water.

(11) The processed asphalts are then re-packaged in larger plastic or fabric bags of various sizes up to 1000 kg.

(12) When the larger bags arrive on site, the processed asphalts are then conveyed directly to the drum/pug-mill in conventional road-paving equipment, where the water content (if present) would be dried along with the process of drying the aggregates. Since there would be no need of a separate blending with refinery bitumen, the sedimenting problem would no longer occur.

(13) The new pellets of pTNA and pVNA and pNNA are of the same material as TNA and VNA and NNA respectively, and when the water content in the pTNA or pVNA or pNNA is remove during the process of drying the aggregates, pTNA or pVNA or pNNA becomes the same material as TLA and VLA and NLA respectively, and therefore acts and performs just as well.

(14) Similarly, the pTLA or pVLA or pVLA is the same material as TLA or VLA or NLA respectively, and acts and performs just as well.

(15) The processed asphalts are user-friendly, cost-effective to the end-user, and the decades of goodwill of successfully using TLA and VLA as a road-paving material could be gained by these pellets produced and used with this new method.

(16) (b) Method Two: Packaging with Surface Water.

(17) Section 4 Item 2(b) shows the flowchart of how this processed asphalts are produced and used.

(18) The process of Method Two is detailed in Section 4 Item 2 (b).

(19) In this method, the natural or refined asphalts are crushed to discrete elements and then soaked with water under defined conditions, and then packaged with the surface water in sealed plastic bags of various sizes, usually up to 45 kg.

(20) The smaller the size of the discrete element, the easier the ability to handle and use the packaged processed asphalt. There is no attempt in this process to change the characteristics of the processed asphalts, and these pellets are still thermoplastic and therefore can flow. Consequently, the discrete elements of the natural or refined asphalt must be crushed to smaller sizes to minimize the actions of any flowing, so that the processed asphalts, when packaged, could still be handled and used. These elements should be about 0.25 kg or smaller.

(21) The only additive is the surface water on the pellets.

(22) The pellets of processed asphalts produced in this method (i.e. Option One (pTNA or pVNA or pNNA), or Option Two (pTLA or pVLA or pNLA)), do not coalesce. Further, as the pellets are introduced to drum/pug-mill where the aggregates are being dried, the surface water and the water content of the pTNA or pVNA or pNNA, or the surface water on the pTLA or pVLA or pNLA, are dried. Therefore, no additives are used in the final road-paving mix. Moreover, when used, and as the surface water and the water content (if present) having been dried prior to the mix, all these processed asphalt acts and perform in the same manner as TLA or VLA or NLA respectively, thereby gaining the decades of goodwill of successfully using these refined asphalts as a road-paving material.

(23) As the pellets are transported via conveyor belts directly to the drum/pug-mill, the sedimenting problem does not occur.

(24) No attempt is made in this process to change the nature of the natural or refined asphalts, and these pellets still flow (minimized by using smaller sizes), the coalescing is solved, and the mineral matters still sediment when blended with refinery bitumen (but this blending is no longer necessary).

(25) (c) Method Three: Processing with Water and Packaged.

(26) Section 4 Item 2(c) shows the flowchart of how these processed asphalts are produced and used.

(27) The process is detailed in Section 4 Item 2 (c).

(28) In this method, only water as an additive is added to the crushed natural or refined asphalt, and the resulting combination is then mixed using a variable speed blender, without added heat, to produce powders or pellets. Pellets are produced at the lower speeds of the blender, and powders are produced at the higher speeds, and the blending time determines both forms (i.e. low blender speeds with longer blending times result in the formation of powders). The temperature during the process increases up to about 10 C. After the blending, the added water is drained and stored for re-use. The resulting processed asphalt of pTNA or pVNA or pNNA, or pTLA or pVLA or pNLA is then either dried with hot air at temperatures between 50 and 60 C., or allowed to dry in the atmosphere, or left with the surface moisture. The dried processed asphalt is then packaged in paper or plastic or fabric bags usually from 10 kg to 1000 kg, and the pellets with surface water is packaged in plastic bags only, usually up to 45 kg. When packaged in plastic bags, the pellets and the plastic bags could be conveyed directly to the drum/pug-mill, as the plastic bags do not adversely affect the performance of the modifier.

(29) The dried processed asphalts (Option Three) are then used on conventional road-paving equipment, transporting the pellets via conveyor belts either directly to the drum/pug-mill (pellets only) for mixing or to the blending tank (pellets or powder) where the refinery bitumen and modifier could be blended, and the resulting blend is then pumped to the drum/pug-mill for mixing.

(30) The pellets of the processed asphalts with surface water (Option Four) are then conveyed directly to the drum/pug-mill where the aggregates are being dried. The surface water (Option Four) and the water content (Option One) are dried at the same time the aggregates are also being dried. The bitumen is then introduced to the drum/pug-mill to produce the hot-mixes for road-paving. The additive is therefore not use in the final road-paving mix.

(31) Added water is the only additive in the process, and this is either removed by draining, or by drying (hot air, atmosphere, or in the drum/pug-mill). Therefore, no additive is used in the final road-paving fix.

(32) Further, the actions of the process change the characteristics of the natural and refined asphalts, resulting in powders and pellets which have more user-friendly characteristics than those of the natural or refined asphalts, in that these powders and pellets do not flow or coalesce. Also, the rate of sedimentation of the mineral matter in the processed asphalt when blended with refinery bitumen is significantly lower than the rate of sedimentation when the refined asphalts are blended with refinery bitumen, thereby allowing, when necessary, to have the dry processed asphalts separately blended with the refinery bitumen on conventional equipment, as the window for use is significantly longer than the four hours allowed with TLA or VLA when used on specialized heated tanks with stirrers.

(33) Since this process uses no additives except water, pTNA or pVNA or pNNA produced from Options One with Four), or pTLA or pVLA or pNLA (produced from Options One or Two with Three) (Section 4 Item 2(c)), when used, are all the same material as the TLA or VLA or NLA, as any surface water or water content present on/in these pellets would be removed during the drying process in the drum/pug-mill prior the final road-paving mix. In addition, the blends of the processed asphalts with refinery bitumen perform as well as, and sometimes better than, similar blends with the TLA or VLA or NLA respectively. This shows that the powders and pellets products by this new method performs as well as the kegged or barreled products produced for decades by the original method (Section 3 Item 7), and pTLA or pVLA or pNLA is easier to handle and use, and is more cost-effective. The decades of goodwill of successfully using TLA and VLA as a road-paving material could therefore be transferred to the powders and pellets produced with this new method.

(34) In the dried powdered form, the pTLA or pVLA or pNLA could also be used to produce the non-paving options, like as a base for coatings, epoxies, chip-board, etc.

(35) (2) The Differences and Improvements.

(36) The Methods detailed in this patent are new in that, amongst others:

(37) (a) Section 3 Item 9 shows an attempt by others to form pellets which do not coalesce. In this attempt, the water content of the natural asphalt of TNA is removed to form a refined asphalt of TLA which is packaged in bulk-form in kegs and barrels, each carrying 250 kg, making it a hazard to handle, an environment problem to discard the containers, and with the same user-unfriendly characteristics (coalescing, cannot be used on conventional equipment, etc.). However, in all the Methods in this patent, the processed asphalts are user-friendly (no coalescing, used on conventional equipment), are packaged in paper or paper or fabric bags of various sizes (between 10 kg and 1000 kg), and easier to handle. The plastics could be thrown with the pellets into the drum/pug-mill in the conventional equipment, and the paper and fabric bags form no environmental problem to discard.

(38) (b) In this attempt by others, a powder is used to stop the pellets of TLA from coalescing, and if or when the powder falls off the pellets during transport, storage or handling, the coalescent problem re-occurs. Further, the powder used to coat the pellets forms a part of the final road-paving mix. Therefore, the powder-coated TLA used is not the same material as TLA, thereby losing the decades of goodwill of TLA as a modifier for road-paving.

(39) However, in Method Two, surface water is used to stop the pellets from coalescing, and when the processed asphalts are used, the surface water is removed in the drum/pug-mill, so that the additive (i.e. surface water) forms no part of the final road-paving mix.

(40) (c) Section 3 Item 10 shows an attempt by others to form pellets which do not coalesce. This attempt is different from Method Three in this patent in that, in Method Three: (i) no high shear mixer is required to reduce the temperature of the action but it is rather the added water which reduces the friction to lower the temperature of the mixture, (ii) the equipment used in this process is a variable speed blender, (iii) the temperature of the TNA with water does not go up to between 160 to 200 C., but only goes up by about 10 C., showing that in Method Three, the process is not temperature dependent, (iv) no stabilizers (like clay or silica or others) are used to increase the melting point, and (v) no stabilizers form a part of the final road-paving mix. In all these Methods in this patent, the additive used (i.e. water) does not form a part of the final road-paving mix, and the pTLA or pVLA or pNLA are respectively the same materials as TLA or VLA or NLA, without any stabilizers.

(41) (d) In method Three, the rate of the sedimentation of the mineral matters in the powders and pellets of pTLA or pVLA or pNLA when blended with refinery bitumen is slowed that the corresponding rates of sedimentation with TLA or VLA or NLA when blended with refinery bitumen.

(42) (e) In order to use refined asphalts in other processes, specialized heated tanks with stirrers are required on-site, but in all these Methods, the pellets and powders produced could be used with conventional road-paving equipment.

(43) (f) The powdered pTLA or pVLA or pNLA formed in Method Three could be used for non-paving options.

(44) (g) In Method One, no additive, not even water, is used.

(45) In Method Two, water is added to the crushed natural or refined asphalts to surround the pellets, and no chemical reaction takes place.

(46) In Method Three, it is the action of the process which changes the characteristics of the natural asphalt, and not any secondary action, as is done by others (see Section 3 Item 10); and

(47) (h) This process applies to all natural asphalts, including TNA and VNA and NNA, which have thermoplastic and coalescent characteristics